Co-reporter:Wensi Zhang, Dongmei Lin, Haixia Wang, Jingfeng Li, Gerd Ulrich Nienhaus, Zhiqiang Su, Gang Wei, and Li Shang
Bioconjugate Chemistry September 20, 2017 Volume 28(Issue 9) pp:2224-2224
Publication Date(Web):August 8, 2017
DOI:10.1021/acs.bioconjchem.7b00312
Metal nanoclusters (NCs) hold great potential as novel luminescent nanomaterials in many applications, while the synthesis of highly luminescent metal NCs still remains challenging. In this work, we report self-assembling peptides as a novel bioinspired scaffold capable of significantly enhancing the luminescence efficiency of gold nanoclusters (AuNCs). The resulting AuNCs capped with motif-designed peptides can self-assemble to form nanofiber structures, in which the luminescence of AuNCs is enhanced nearly 70-fold, with 21.3% quantum yield. The underlying mechanism responsible for the luminescence enhancement has been thoroughly investigated by the combined use of different spectroscopic and microscopic techniques. The resultant highly luminescent AuNC-decorated peptide nanofibers exhibit physicochemical properties that are advantageous for biological applications. As a proof of concept, we demonstrate the use of these nanostructure as fluorescent thermometers and for imaging living cells, both showing very promising results.
Co-reporter:Xiaoqing Yu, Dongmei Lin, Peng Li, Zhiqiang Su
Solar Energy Materials and Solar Cells 2017 Volume 172(Volume 172) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.solmat.2017.07.045
•The performance and nanostructures of pure TiO2 were discussed.•Different methods for preparing TiO2-graphene nanohybrids were compared.•Some energy applications based on TiO2-graphene nanohybrids were summarized.Owing to its excellent optical, electronic properties, good chemical and thermal stability, titanium dioxide (TiO2) has been applied in promising energy technologies including new dye-sensitized solar cells, rechargeable batteries, supercapacitors, photocatalysts and gas sensors in recent years. However, wide band gap and poor electron transporting ability of TiO2 has largely limited its application in some aspects like photocatalytic hydrogen generation and lithium ion batteries. Therefore, the modification of TiO2 is essential for improving its optical and electrical properties. Graphene (GR), a two dimensional carbon nanostructure, is an ideal material to modify TiO2 owing to its excellent electronic transport properties, exceptional thermal, and electrical conductivity. Compared to a pure TiO2 nanostructure, the conjugation of GR leads to the increase of its adsorption capacity and photocatalytic activity, and improve the electrical conductivity and Li-ion diffusion pathways. In this review, we have firstly discussed pure TiO2 nanostructures and introduced different methods for the preparation of TiO2-graphene nanohybrids (TiO2-GRNHs), and then discussed the practical applications of the TiO2-GRNHs in different energy technologies. It is expected that the continuous breakthroughs in the synthesis and modifications of TiO2-GRNHs will bring new high-performance materials with exotic properties and potential applications in emerging energy technologies.Download high-res image (254KB)Download full-size image
Co-reporter:Tianjiao Liu, Junwei Ding, Zhiqiang Su, Gang Wei
Materials Today Energy 2017 Volume 6(Volume 6) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.mtener.2017.08.006
•The different fabrication strategies of the porous 2D materials were introduced.•The special structures and properties of the porous 2D materials were mentioned.•The various energy applications of the porous 2D materials were discussed.Due to their unique structure and properties as well as promising applications, porous two-dimensional (2D) materials, such as graphene, boron nitride, metal chalcogenides, carbon nitride, and metal oxides, have attracted extensive attention in the past few years. Combining the advantages of both 2D materials and porous structure, the fabricated porous 2D materials have presented the features of large surface areas, diversified compositions, and enhanced electronic conductivity, which endow them high potentials to act as defining components in high-performance electrochemical energy storage and conversion devices, such as lithium-ion batteries, sodium-ion batteries, supercapacitors, and fuel cells. In this review, we demonstrated the fabrication of various porous 2D materials by using several typical techniques like surface treatment, self-assembly, vacuum filtration, template-based, and template-free synthesis. In another way, their potential applications in energy sciences and the main challenges were introduced and discussed. It is expected that this work will be helpful for understanding the effects of material structure on its electrochemical performances in one way, and in another way will guide the design and fabrication of novel porous 2D structured materials for energy, electronic, and biomaterial applications.Download high-res image (244KB)Download full-size image
Co-reporter:Mingfa Zhang;Xinne Zhao;Guanghua Zhang;Gang Wei
Journal of Materials Chemistry B 2017 vol. 5(Issue 9) pp:1699-1711
Publication Date(Web):2017/03/01
DOI:10.1039/C6TB03121H
Electrospinning represents a simple and effective strategy for fabricating nanofibrous structures and materials with large surface-to-volume ratios and desirable engineered properties. Thus, incorporating nanoscale building blocks (NBBs) like nanoparticles, graphene quantum dots, carbon nanotubes, and graphene into electrospun fibers has become one of the most attention-getting research topics in the field of biosensing. However, the dispersion behavior of NBBs in the nanofibers, the limited surface area of nanofibers and the insufficient immobilization sites for tested biomolecules still restrict the better performances and broader applications of the fabricated biosensors. In this review, we present a comprehensive survey of strategies that have been utilized to fabricate functional fibrous nanostructures for the amplification of the detection signals of nanostructure-based biosensors. In particular, from the perspective of design configuration, we systematically summarized recent advances in the electrospinning fabrication of hybrid polymer nanofibers decorated with functionalized NBBs. The strategies for promoting better dispersion of NBBs in electrospun nanofibers, including direct blending before electrospinning and in situ synthesis during electrospinning, are introduced in detail. In addition, some effective processing routes for increasing immobilization sites of tested biomolecules such as arrangement of NBBs and morphological processing of nanofibers are also presented. In addition, the suitability of electrospun nanostructures for biosensors, and the advantages and disadvantages of each method for improving the biosensing performance are also discussed.
Co-reporter:Xiaoqing Yu;Zhenping Wang;Gang Wei
Journal of Materials Chemistry B 2017 vol. 5(Issue 6) pp:1130-1142
Publication Date(Web):2017/02/08
DOI:10.1039/C6TB02659A
By specifically binding with various inorganic nanomaterials through their functional groups or introducing special reactivity, the nanostructures and biofunctions of designed peptides can be enriched. This review provides a brief discussion on the design, composition, and biomedical applications of bioinspired peptide–inorganic nanomaterial hybrids. The attaching mechanisms of different peptide–inorganic nanomaterials are discussed from the viewpoint of the functional group, nanostructure, and conformational freedom. Particularly, the structures and functions of the obtained hybrids based on different nanomaterials are described in detail. In addition, we highlight some examples of self-assembled peptide–inorganic nanomaterial systems with relevance to biomedical applications, including biosensors, cell targeting, bioimaging, biomineralization, biocatalysts, and drug delivery. We also give a short outlook on the broad prospects of the fabrication and applications of peptide–inorganic nanomaterial hybrids.
Co-reporter:Keheng Li;Wei Liu;Yao Ni;Dapeng Li;Dongmei Lin;Gang Wei
Journal of Materials Chemistry B 2017 vol. 5(Issue 25) pp:4811-4826
Publication Date(Web):2017/06/28
DOI:10.1039/C7TB01073G
Graphene quantum dots (GQDs) have generated enormous excitement because of their superiority in chemical inertness, biocompatibility and low toxicity. Due to quantum confinement and edge effects, GQDs have excellent properties, attracting extensive attention from scientists in the fields of chemistry, physics, materials science, biology, and other interdisciplinary sciences. In this review, we aim to present a comprehensive view on the synthesis of GQDs for biological applications. We highlight potential methods like acid oxidation, hydrothermal and solvothermal reactions, microwave-assisted methods, electrochemical oxidation, as well as pyrolysis and carbonization for the successful preparation of GQDs. Meanwhile, four representative types of biomedical application based on GQDs, bioimaging, biosensing, drug delivery, and antimicrobial materials, are introduced and discussed in detail. This work will be very useful for quickly gaining knowledge and experience for synthesizing various GQDs, and developing advanced strategies for creating novel functional GQD-based nanomaterials for further applications in biomedicine, materials science, analytical science, and optical nanodevices.
Co-reporter:Yang Li;Panpan Zhang;Zhaofei Ouyang;Mingfa Zhang;Zhoujun Lin;Jingfeng Li;Gang Wei
Advanced Functional Materials 2016 Volume 26( Issue 13) pp:2122-2134
Publication Date(Web):
DOI:10.1002/adfm.201504533
The performance of graphene-based hybrid materials greatly depends on the dispersibility of nanoscale building blocks on graphene sheets. Here, a quick green synthesis of nanoscale graphene (NG) nanosheets decorated with highly dispersed silver nanoparticles (AgNPs) is demonstrated, and then the electrospinning technique to fabricate a novel nanofibrous membrane electrode material is utilized. With this technique, the structure, mechanical stability, biochemical functionality, and other properties of the fabricated membrane electrode material can be easily controlled. It is found that the orientations of NG and the dispersity of AgNPs on the surface of NG have significant effects on the properties of the fabricated electrode. A highly sensitive H2O2 biosensor is thus created based on the as-prepared polymeric NG/AgNP 3D nanofibrous membrane-modified electrode (MME). As a result, the fabricated biosensor has a linear detection range from 0.005 to 47 × 10−3m (R = 0.9991) with a supralow detection limit of 0.56 × 10−6m (S/N = 3). It is expected that this kind of nanofibrous MME has wider applications for the electrochemical detection and design of 3D functional nanomaterials in the future.
Co-reporter:Dongmei Lin, Yang Li, Panpan Zhang, Wensi Zhang, Junwei Ding, Jingfeng Li, Gang Wei and Zhiqiang Su
RSC Advances 2016 vol. 6(Issue 58) pp:52739-52745
Publication Date(Web):24 May 2016
DOI:10.1039/C6RA07591F
Molybdenum disulfide (MoS2) has shown increasing importance for the creation of functional nanomaterials. Here we demonstrate the quick preparation of MoS2 nanoflowers decorated with platinum nanoparticles (PtNPs) by a simple one-step hydrothermal synthesis. Scanning and transmission electron microscopy techniques were utilized to investigate the morphology of the fabricated MoS2–PtNP nanohybrids and the uniform decoration of PtNPs on MoS2. Other techniques like X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray diffraction were used to measure the structure and properties of the synthesized MoS2–PtNP nanohybrids. We expected the created MoS2–PtNP nanohybrids to show excellent performance for biosensor applications. To prove this, the synthesized MoS2–PtNP nanohybrids were utilized in the application of an electrochemical hydrogen peroxide (H2O2) sensor by using the nanohybrids to modify the glass carbon electrode. Our sensing result indicates that the fabricated MoS2–PtNP based H2O2 sensor reveals a wide linear range (0.02 to 4.72 mM), low detection limit (0.345 μM, S/N = 3), high selectivity, and long-term stability (at least two weeks).
Co-reporter:Junwei Ding, Tianjiao Liu, Wei Sun, Jingfeng Li, Gang Wei, Zhiqiang Su
Sensors and Actuators B: Chemical 2016 Volume 236() pp:450-458
Publication Date(Web):29 November 2016
DOI:10.1016/j.snb.2016.06.026
•Ternary Mn-Mo-O hybrid materials were synthesized by one-step hydrothermal reaction.•The carambola-shaped ternary Mn-Mo-O hybrid material was prepared successfully.•The formation mechanism of carambola-shaped ternary Mn-Mo-O was proposed.•The Mn-Mo-O based electrochemical N2H4 sensor shows excellent performance.Novel ternary Mn-Mo-O hybrid materials were synthesized via a simple hydrothermal route, and their structures were directly confirmed and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray powder diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy techniques. The different influence factors on the hydrothermal synthesis of the carambola-shaped ternary Mn-Mo-O hybrid materials were studied, and the mechanism for the hydrothermal synthesis of carambola-shaped ternary Mn-Mo-O hybrid material was also presented. Furthermore, the synthesized ternary Mn-Mo-O hybrid material was immobilized onto glassy carbon electrode and applied to construct an electrochemical hydrazine (N2H4) sensor. It was found that the fabricated N2H4 sensor exhibited a fast amperometric response to N2H4 with a wide linear range (0.1 μM–1.4 mM) and low detection limit (0.045 μM). Such novel ternary Mn-Mo-O hybrid materials represent promising nonenzymatic electrochemical N2H4 sensor with the intermediate level sensitivity, good selectivity, improved stability, and fast amperometric response.The ternary Mn-Mo-O hybrid material synthesized by the one-step hydrothermal reaction shows high performance for the electrochemical sensing N2H4.
Co-reporter:Zhiqiang Su;Huiyan Shen;Haixia Wang;Jinhui Wang;Jingfeng Li;Gerd Ulrich Nienhaus;Li Shang;Gang Wei
Advanced Functional Materials 2015 Volume 25( Issue 34) pp:5472-5478
Publication Date(Web):
DOI:10.1002/adfm.201502506
Nanohybrids based on biomolecular nanostructures and graphene quantum dots (GQDs) have found wide application in the biological and biomedical fields. Herein, the design of a peptide with trifunctional motifs is reported as the precursor building block for constructing a novel multifunctional protein nanofiber (PNF), and further conjugated with highly fluorescent GQDs by noncovalent interactions. The physicochemical properties of these PNF–GQD nanohybrids are thoroughly characterized by a variety of spectroscopic and microscopic techniques, revealing that the GQDs essentially maintain their favorable optical properties in the nanohybrids. A good biocompatibility of the PNF–GQD nanohybrids is found with cell viability assays. With both, a recognition moiety (RGD) and an imaging probe (GQD), these PNF–GQD nanohybrids possess the capability of targeting and imaging tumor cells simultaneously. A potential application of these novel nanohybrids, i.e., fluorescence imaging of HeLa tumor cells, has been investigated by confocal fluorescence microscopy, which shows much enhanced labeling efficiency compared with GQDs only. Moreover, cellular internalization by nontumorous COS-7 cells was much weaker than by HeLa cells. Our results show that GQD-decorated PNF nanohybrids have great potential as multifunctional platforms for biomedical applications, particularly, where the capability of sensitive tracking and efficient labeling is appreciated.
Co-reporter:Yang Li, Xiaojia Zhao, Panpan Zhang, Jing Ning, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2015 vol. 3(Issue 16) pp:4126-4133
Publication Date(Web):13 Mar 2015
DOI:10.1039/C5TC00196J
We demonstrated here a facile approach to produce a large-scale reduced graphene oxide–silver nanoparticle (RGO–AgNP) hybrid film, and further explored its application as a highly active surface-enhanced Raman scattering (SERS) substrate. The RGO–AgNP nanohybrids were firstly synthesized by reducing graphene oxide (GO) and Ag+ cations with sodium citrate, and the RGO–AgNP hybrid film was then fabricated by evaporating the RGO–AgNP nanohybrids solution and harvesting the film formed at the air–liquid interface with a solid substrate. Two probe molecules, Rhodamine 6G (R6G) and melamine (MA), were chosen to evaluate the enhancement performance of the fabricated SERS-active substrate. Our results indicated that this RGO–AgNP hybrid film-based SERS-active substrate presents outstanding performances for detecting R6G with an enhancement factor of 2.3 × 106 and a detection limit of approximately 1.0 × 10−12 M. In addition, this SERS substrate shows excellent ability to recognize MA molecules with a detection limit of approximately 1.0 × 10−7 M.
Co-reporter:Panpan Zhang, Xinne Zhao, Yuanchun Ji, Zhaofei Ouyang, Xin Wen, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2015 vol. 3(Issue 12) pp:2487-2496
Publication Date(Web):02 Feb 2015
DOI:10.1039/C4TB02092H
Graphene quantum dots (GQDs) have become increasingly important for applications in energy materials, optical devices and biosensors. Here we report a facile technique to fabricate a nanofibrous membrane of GQDs by electrospinning water-soluble GQDs with polyvinyl alcohol (PVA) directly. The structure and fluorescence properties of the fabricated PVA/GQD nanofibrous membrane were investigated using scanning and transmission electron microscopy, and fluorescence microscopy. It was found that the electrospun PVA/GQD nanofibrous membrane has a three-dimensional structure with a high surface area to volume ratio, which is beneficial for the adsorption of electrolytes and the diffusion of reactants. For the first time, the created PVA/GQD nanofibrous membrane was utilized to fabricate dual-purpose fluorescent and electrochemical biosensors for highly sensitive determination of hydrogen peroxide (H2O2) and glucose. The experimental results indicated that the fluorescence intensity of the nanofibrous membrane decreased linearly with increasing H2O2 concentration, because the addition of H2O2 leads to fluorescence quenching of the GQDs, which endows the fabricated nanofibrous membrane with fluorescence activity. Besides, after binding glucose oxidase onto the created nanofibrous membrane, the fabricated nanofibrous membrane showed high sensitivity and selectivity for glucose detection. In addition, the PVA/GQD nanofibrous membrane can also be directly electrospun onto an electrode for electrochemical detection of H2O2. This novel nanofibrous membrane exhibits excellent catalytic performance and fluorescence activity, and therefore has potential applications for the highly stable, sensitive, and selective detection of H2O2 and glucose.
Co-reporter:Panpan Zhang, Xueyi Lu, Ying Huang, Junwen Deng, Lin Zhang, Fei Ding, Zhiqiang Su, Gang Wei and Oliver G. Schmidt
Journal of Materials Chemistry A 2015 vol. 3(Issue 28) pp:14562-14566
Publication Date(Web):15 Jun 2015
DOI:10.1039/C5TA02945G
We demonstrate here a facile one-step hydrothermal synthesis to prepare molybdenum disulfide nanosheets decorated with gold nanoparticles (MoS2/AuNPs) for rechargeable Li–O2 batteries. The fabricated Li–O2 battery exhibits enhanced specific capacity and cycle efficiency, which are ascribed to the two-dimensional structure of MoS2/AuNP nanohybrids and the synergistic catalytic effects of both MoS2 nanosheets and AuNPs.
Co-reporter:Jinhui Wang, Zhaofei Ouyang, Zhiwei Ren, Jingfeng Li, Panpan Zhang, Gang Wei, Zhiqiang Su
Carbon 2015 Volume 89() pp:20-30
Publication Date(Web):August 2015
DOI:10.1016/j.carbon.2015.03.024
In this study, self-assembled peptide nanofibers (PNFs) were firstly created with a specially designed peptide molecule. Graphene oxide (GO) nanosheet, as a two-dimensional scaffold, was then modified with the prepared PNFs to fabricate a new type of GO–PNF nanohybrid, which was further utilized as a template for biomimetic mineralization. The produced GO–PNF nanohybrid and its minerals were characterized by atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The obtained results indicate that the created GO–PNF nanohybrid facilitates the nucleation and growth of hydroxyapatite (HA) crystals. The created PNFs promote the formation of HA nanocrystals along the axis of PNFs within short-term incubation and the GO nanosheet mediates the formation of HA microsphere after long-term mineralization. The effects of the produced GO–PNF nanohybrid and biomimetic minerals (GO–PNF–HA) on the adhesion and proliferation of L-929 cells and MC3T3-E1 cells were further investigated. The cell culture result indicates that the produced GO–PNF–HA minerals have good biocompatibility and can enhance the proliferation ability of the studied cells. We believe this novel biocompatible nanohybrid will show great potentials in tissue engineering.
Co-reporter:Panpan Zhang, Haixia Wang, Xiaoyuan Zhang, Wei Xu, Yang Li, Qing Li, Gang Wei and Zhiqiang Su
Biomaterials Science 2015 vol. 3(Issue 6) pp:852-860
Publication Date(Web):28 Apr 2015
DOI:10.1039/C5BM00058K
Graphene and silver nanoparticles (AgNPs) are important building blocks for the synthesis of functional nanomaterials for bio-related applications. Here, we report a facile strategy to decorate AgNPs onto reduced graphene oxide (RGO) by the simultaneous reduction of silver ions and graphene oxide nanosheets within one system, and further to fabricate a dimension-adjustable RGO/AgNP multi-layered film by a thermal-driven self-assembly process. The structures of the fabricated RGO/AgNP hybrid films were identified by UV-visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy. The thickness of the fabricated RGO/AgNP film was further measured by scanning electron microscopy. The hydrophilicity of the RGO/AgNP films was tested by contact angle measurement. Antibacterial and cell culture experiments based on the fabricated RGO/AgNP films indicate that this kind of hybrid film exhibits excellent antibacterial activity and high biocompatibility. A potential antibacterial mechanism of the fabricated RGO/AgNP hybrid film was proposed.
Co-reporter:Junwei Ding, Tianjiao Liu, Wei Xu, Hang Liao, Jingfeng Li, Gang Wei and Zhiqiang Su
RSC Advances 2015 vol. 5(Issue 98) pp:80719-80727
Publication Date(Web):16 Sep 2015
DOI:10.1039/C5RA14035H
Sulfur-doped γ-MnOOH rods were successfully prepared by employing a one-step hydrothermal process based on thioacetamide (TAA), and their structure was directly confirmed and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. The mechanism for the TAA assisted hydrothermal synthesis of γ-MnOOH rods has been preliminarily presented. Furthermore, the synthesized sulfur-doped γ-MnOOH rods were immobilized onto a glassy carbon electrode and applied to construct an electrochemical hydrazine sensor, which exhibited a wide linear range (0.1 μM–1.15 mM and 1.15–45.75 mM), low detection limit (0.079 μM), high selectivity, and long-term stability.
Co-reporter:Junwei Ding, Kai Zhang, Gang Wei and Zhiqiang Su
RSC Advances 2015 vol. 5(Issue 85) pp:69745-69752
Publication Date(Web):11 Aug 2015
DOI:10.1039/C5RA10370C
Polypyrrole nanoplates (PPyNPTs) were successfully synthesized via in situ chemical oxidation polymerization of pyrrole molecules. Furthermore, silver and gold nanoparticles (Ag and AuNPs) were assembled onto the as-prepared PPyNPTs by electrostatic interaction to fabricate two nanohybrids of PPyNPT–Ag and PPyNPT–Au, and their structures were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The optimal parameters for creating uniform PPyNPT–Ag and PPyNPT–Au nanohybrids were obtained by controlling the reactive conditions, and the created PPyNPT–Ag and PPyNPT–Au nanohybrids were then immobilized onto glassy carbon electrodes and applied to construct hydrogen peroxide (H2O2) and dopamine (DA) sensors. We found that the fabricated sensors with PPyNPT–Ag and PPyNPT–Au nanohybrids are highly specific for sensing H2O2 and DA, respectively. The PPyNPT–Ag based H2O2 sensor exhibited a fast amperometric response to H2O2 with a linear range from 0.01 mM to 3.01 mM and a detection limit of 1.8 μM, and the PPyNPT–Au based DA sensor has a linear detection range from 1 μM to 5.201 mM and a detection limit of 0.36 μM.
Co-reporter:Junwei Ding, Wei Sun, Gang Wei and Zhiqiang Su
RSC Advances 2015 vol. 5(Issue 44) pp:35338-35345
Publication Date(Web):13 Apr 2015
DOI:10.1039/C5RA04164C
We report here a facile one-step green synthesis of cuprous oxide microspheres (Cu2OMS) on reduced graphene oxide (RGO) by reducing Cu2+ ions and GO with sodium ascorbate synchronously in the presence of sodium hydroxide. Cu2OMS with different sizes on the surface of RGO were successfully synthesized by adjusting the mass ratio of GO to CuSO4·5H2O in this reaction system. It was found that uniform Cu2OMS were formed on RGO by increasing the mass ratio from 1:20 to 1:80. The synthesized Cu2OMS–RGO composites with different structures were immobilized onto glassy carbon electrodes and applied to construct electrochemical hydrogen peroxide (H2O2) and glucose sensors. The results indicate that the Cu2OMS–RGO composite created with the mass ratio of 1:80 presents the best sensor performances. The fabricated H2O2 sensor exhibits a fast amperometric response to H2O2 with a linear detection range from 0.005 to 2.775 mM and a detection limit of 0.0108 mM, and the glucose sensor has a linear detection range from 0.001 to 0.419 mM and a detection limit of 7.288 × 10−4 mM. The superior performance is ascribed to the unique structure of the synthesized Cu2OMS and the excellent conductivity of the RGO content. In addition, the synthesized Cu2OMS–RGO composites exhibited improved electrochemical stability. Such novel Cu2OMS–RGO hybrid materials represent promising non-enzymatic electrochemical glucose and H2O2 sensors with high sensitivity and selectivity, improved stability, and fast amperometric response.
Co-reporter:Junwei Ding, Shiying Zhu, Tao Zhu, Wei Sun, Qing Li, Gang Wei and Zhiqiang Su
RSC Advances 2015 vol. 5(Issue 29) pp:22935-22942
Publication Date(Web):24 Feb 2015
DOI:10.1039/C5RA00884K
We report here a facile synthesis of different zinc oxide (ZnO) nanostructures on reduced graphene oxide (RGO) by an in situ hydrothermal reaction. ZnO nanostructures with different morphologies on the surface of RGO were successfully synthesized by adjusting the mass ratio of Zn2+ to RGO in this reaction system. It was found that ZnO nanostructures with nanoparticles, mixed nanoparticles and microspindles, and microspindles were formed on RGO by adjusting the mass ratio of Zn2+ to RGO. The synthesized ZnO–RGO nanocomposites with different structures were immobilized onto glassy carbon electrodes and applied to construct electrochemical hydrazine (N2H4) sensors. The results indicate that the ZnO–RGO nanocomposites created with the mass ratio of 4.4:1 present the best sensor performance. The fabricated N2H4 sensor exhibited a fast amperometric response to N2H4 with a linear detection range from 1.0 μM to 33.5 mM and a detection limit of 0.8 μM. The superior performance is ascribed to the unique structure of the synthesized ZnO and the excellent conductivity of RGO. In addition, we found that the synthesized ZnO–RGO composites exhibited improved electrochemical stability. Such novel ZnO–RGO hybrid materials represent promising nonenzymatic electrochemical N2H4 sensors with high sensitivity and selectivity, improved stability, and fast amperometric response.
Co-reporter:Jinhui Wang, Haixia Wang, Yizhu Wang, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2014 vol. 2(Issue 42) pp:7360-7368
Publication Date(Web):08 Sep 2014
DOI:10.1039/C4TB01324G
Layer-by-layer (LBL) assembly is a simple and effective method for the fabrication of a three-dimensional (3D) scaffold for nanotechnological and biomedical applications. Herein, a novel 3D scaffold based on an alternate LBL assembly of graphene oxide (GO) nanosheets and fibrinogen nanofibers (Fg NFs) on a silicon substrate was fabricated and utilized to create a 3D hydroxyapatite (HA) scaffold by biomimetic mineralization in 1.5× simulated body fluid for different nucleation periods. The obtained 3D (GO–NF)n–HA scaffold was characterized using atomic force microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results demonstrate that the Fg NFs could promote the nucleation and growth of HA crystals along the axis. The 3D (GO–NF)10–HA scaffold composed of 10 layers of GO alternating with 10 layers of NFs was successfully created by LBL assembly and subsequent biomimetic mineralization. The effects of the created 3D (GO–NF)10–HA scaffolds on the adhesion, morphology, and proliferation of L-929 cells were investigated. The in vitro cell culture indicates that the 3D (GO–NF)10–HA scaffold has a higher proliferation ability and better cytocompatibility than the other control samples.
Co-reporter:Haixia Wang, Dianming Sun, Nana Zhao, Xinchao Yang, Yuzhou Shi, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2014 vol. 2(Issue 10) pp:1362-1370
Publication Date(Web):06 Dec 2013
DOI:10.1039/C3TB21538E
We report the covalent interaction mediated assembly of thermo-sensitive polymer nanoparticles (PNPs) on functionalized graphene oxide (GO) nanosheets to create novel GO–PNP hybrids for drug delivery. To this end, thermo-sensitive PNPs with an average diameter of about 50 ± 12 nm were first synthesized with the free radical polymerization reaction, and GO nanosheets were noncovalently modified with a bifunctional linker to provide reactive sites for the binding of PNPs. Finally, GO–PNP hybrids were successfully synthesized by the covalent interaction mediated assembly of PNPs on GO nanosheets. Multi-characterization techniques were utilized to identify the formation of PNPs, the modification of GO nanosheets, and the formation of GO–PNP hybrids. Cell culture experiment with the mouse osteoblast-like MC3T3-E1 cells indicates that the synthesized GO–PNP hybrids have satisfactory biocompatibility. The loading efficiency of drug molecules (Adriamycin, ADR) with GO–PNP (∼87%) is close to that with GO (∼91%), but significantly higher than that with PNPs (∼46%). The release efficiency of GO–PNP hybrids with the highest surface coverage of PNPs (∼85 PNPs per μm2) is about 22%, which is very close to that of PNPs (∼25%) and significantly higher than that of GO (∼11%). Our study indicates that this thermo-sensitive GO–PNP hybrid, when considering the drug loading and release comprehensively, has better performance than both PNPs and GO and thus can be used as a novel nanocarrier for temperature-controllable drug release. The GO–PNP hybrids with and without ADR were applied to kill cancer cells in vitro and the result shows that the GO–PNP hybrid with ADR has an obvious effect on killing cancer cells, and its performance is obviously better than both GO and PNPs. It is expected that this new hybrid material based on GO and PNPs will have great potential for in vivo applications such as to kill target cancer cells by modifying with specific antibodies.
Co-reporter:Xiaojia Zhao, Yang Li, Jinhui Wang, Zhaofei Ouyang, Jingfeng Li, Gang Wei, and Zhiqiang Su
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 6) pp:4254
Publication Date(Web):March 3, 2014
DOI:10.1021/am405983a
We report a facile in situ synthesis of reduced graphene oxide (RGO)–phenol formaldehyde (PF) composites with an interactive oxidation–reduction reaction. In this interactive chemical reaction, graphene oxide (GO) was reduced to RGO by phenol, and simultaneously phenol was oxidized to benzoquinone. The noncovalently adsorbed phenol on the RGO surface can not only serve as an effective reductant but also participate in the in situ polymerization and guide the formation of PF on the RGO surface. RGO–PF composites with different RGO contents were prepared successfully and further characterized with fluorescent spectroscopy, scanning electron microscopy, and transmission electron microscopy. The mechanical strength, electrical conductivity, thermal conductivity, and thermal resistance of the created RGO–PF were investigated. The results indicated that the dispersity of RGO in the PF matrix and the interfacial interaction between RGO and PF were improved greatly because of formation of the RGO–PF hybrid in the in situ synthesis. The homogeneous dispersion and in situ polymerization of RGO sheets help to enhance the thermal conductivity of RGO–PF composites from 0.1477 to 0.3769 W m–1 K–1 and endow the composites with a good electrical conductivity. In addition, the well-dispersed RGO–PF composites are much more effective in improving their mechanical property and heat resistance.Keywords: graphene oxide; in situ polymerization; oxidation−reduction reaction; phenol formaldehyde; property;
Co-reporter:Panpan Zhang, Xinne Zhao, Xuan Zhang, Yue Lai, Xinting Wang, Jingfeng Li, Gang Wei, and Zhiqiang Su
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 10) pp:7563
Publication Date(Web):April 10, 2014
DOI:10.1021/am500908v
A novel β-phase polyvinylidene difluoride (PVDF) nanofibrous membrane decorated with multiwalled carbon nanotubes (MWCNTs) and platinum nanoparticles (PtNPs) was fabricated by an improved electrospinning technique. The morphology of the fabricated PVDF–MWCNT–PtNP nanofibrous membrane was observed by scanning electron microscopy, and the formation of high β-phase in the hybrid nanofibrous membrane was investigated by Fourier transform infrared spectroscopy and differential scanning calorimetry. The uniform dispersion of MWCNTs and PtNPs in the PVDF hybrid nanofibrous membrane and their interaction were explored by transmission electron microscopy and X-ray diffraction. For the first time, we utilized this created PVDF–MWCNT–PtNP nanofibrous membrane for biosensor and catalysis applications. The nonenzymatic amperometric biosensor with highly stable and sensitive, and selective detection of both H2O2 and glucose was successfully fabricated based on the electrospun PVDF–MWCNT–PtNP nanofibrous membrane. In addition, the catalysis of the hybrid nanofibrous membrane for oxygen reduction reaction was tested, and a good catalysis performance was found. We anticipate that the strategies utilized in this work will not only guide the further design of functional nanofiber-based biomaterials and biodevices but also extend the potential applications in energy storage, cytology, and tissue engineering.Keywords: application; biosensor; catalysis; electrospun; nanofibrous membrane;
Co-reporter:Jinhui Wang, Xiaojia Zhao, Jingfeng Li, Xiao Kuang, Yuqian Fan, Gang Wei, and Zhiqiang Su
ACS Macro Letters 2014 Volume 3(Issue 6) pp:529
Publication Date(Web):May 22, 2014
DOI:10.1021/mz500213w
Biomacromolecules and their assemblies have the unique ability for biomimetic promotion of the formation of novel and functional nanomaterials. In this work, artificial peptide nanofibers were created with a special designed peptide molecule that contains complex motif sequences and then further metallized to synthesize nanofiber-based silver nanowires. A novel hybrid nanomaterial was obtained successfully by assembling the prepared silver nanowires on graphene nanosheets, and its potential application in nonenzymatic electrochemical H2O2 sensing was explored. This fabricated sensor based on graphene and silver nanowires exhibits high sensitivity and selectivity, low detection limit, and wide linear range for the determination of H2O2.
Co-reporter:Li Cao, Dunfan Su, Zhiqiang Su, and Xiaonong Chen
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 6) pp:2308-2317
Publication Date(Web):January 23, 2014
DOI:10.1021/ie403746p
A novel multiwalled carbon nanotube/polypropylene (CNT/PP) conductive fibrous membrane with fiber diameter of 1–3 μm was fabricated by melt electrospinning. To improve the dispersibility of CNT and enhance the spinnability of PP fibers, CNTs were first mixed with small amounts of paraffin liquid (PL) and then melt-blended with PP for melt electrospinning. The morphology of fibrous membranes and the orientation of CNTs in PP fibers were observed via scanning and transmission electron microscopy (SEM and TEM). The effect of PL and CNTs on crystallization behavior of PP was studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Tensile test and impedance analysis were performed to investigate the mechanical and electrical properties of the fibrous membranes. The results indicated that CNT has a distinct nucleating effect on PP, and the addition of PL can improve the spinnability of the CNT/PP compound remarkably. This novel conductive fibrous membrane fabricated by melt electrospinning exhibits improved tensile strength and modulus, good electric conductivity, and enhanced dielectric constant and hydrophobicity.
Co-reporter:Xiaoyuan Zhang, Zhaofei Ouyang, Robert Schulze, Thomas F. Keller, Klaus D. Jandt and Zhiqiang Su
RSC Advances 2014 vol. 4(Issue 16) pp:7900-7910
Publication Date(Web):09 Jan 2014
DOI:10.1039/C3RA47499B
Various microstructures and phase morphologies of an amphiphilic poly(ethylene oxide)-block-polyethylene (PEO-b-PE) co-oligomer, controlled by topological restriction of PE segments on the tethered PEO chains, were characterized by differential scanning calorimetry (DSC), polarized optical microscopy (POM), scanning electron microscopy (SEM), and synchrotron radiation wide-angle/small-angle X-ray scattering (WAXS/SAXS) in drop-cast films. The crystallization processes were mediated by two pathways, a one-step crystallization process (I) and a sequential crystallization process (II). Results show that the thermal procedures have great influence on the microstructures and phase morphologies of PEO-b-PE co-oligomer, e.g., negative spherulites with radial stripes were detected in the one-step crystallization process (I), while crystalline texture, which contains a large number of crystals with reduced sizes, formed in the sequential crystallization process (II). Based on our experimental data, the topological restriction effect encountered by PEO chains depends on the hard confinement of PE crystals and the soft confinement of amorphous PE in the two crystallization procedures. The formation mechanisms of the long-range order structures within the co-oligomer were elucidated through morphology models. These nano-patterned structures make the double crystalline block copolymers outstanding candidates for surface modification, micromolding, and optoelectronic devices in nanotechnological and biomedical applications.
Co-reporter:Qing Li;Xiaoyuan Zhang;Jingfeng Li;Zhaofei Ouyang;Haixia Wang;Gang Wei
Polymer Engineering & Science 2014 Volume 54( Issue 9) pp:2112-2120
Publication Date(Web):
DOI:10.1002/pen.23760
We report here the synthesis and characterization of a reactive liquid crystal (RLC) as a novel polymeric nucleating agent for the promotion of the nucleation efficiency of isotactic polypropylene (iPP). The RLC was synthesized by an in-situ photo-polymerization and was then grafted onto the molecular chain of iPP by the reactive blending. The phase transition and crystalline morphologies of RLC-iPP in the β-nucleation were studied. It is found that the nucleation efficiency of β-crystals of iPP can be increased to 42% with a very small amount of RLC grafting, which is much higher than the reported nucleation efficiency of polymeric nucleating agents up to now (23%). In addition, we found that the nucleation efficiency of β-crystals is strongly related to the concentration of RLC for the reactive blending. The nucleation efficiency was decreased from 42% to about 17% with the increase of RLC concentration from 0.5% to 4%. We propose a possible nucleation mechanism for this interesting phenomenon. It is expected that this new β-nucleation RLC will have potential industrial applications in the future. POLYM. ENG. SCI., 54:2112–2120, 2014. © 2013 Society of Plastics Engineers
Co-reporter:Li Cao;Dun-fan Su;Zhi-qiang Su 苏志强
Chinese Journal of Polymer Science 2014 Volume 32( Issue 9) pp:1167-1175
Publication Date(Web):2014 September
DOI:10.1007/s10118-014-1465-2
β-nucleated isotactic polypropylene (iPP) fibers with diameters less than 5 μm were prepared through melt electrospinning. The effects of electrospinning process and rare earth β-nucleating agent (WBG) on the crystal structure of iPP fibers were investigated. The results indicate that the addition of WBG can improve the fluidity of iPP melt remarkably and help the formation of fine fibers with thinner diameter, while the electrostatic force applied on the iPP melt is not favorable for the formation of β-crystal in iPP fibers. In addition, the morphology and crystalline structure of WBG/iPP electrospun fibers depended on the content of WBG. Both the crystallinity and the percentage of β-crystal form of WBG/iPP electrospun fibers increase with the rise of the content of nucleating agent, which endows the prepared electrospun fibers excellent mechanical properties. The β-nucleated iPP electrospun fibrous membranes prepared in this study can be used for protective clothing material, filtration media, reinforcement for composites and tissue engineering scaffolds.
Co-reporter:Xiaoyuan Zhang, Robert Schulze, Panpan Zhang, Claudia Lüdecke, Xiuqin Zhang, Zhiqiang Su, Klaus D. Jandt
Polymer 2014 Volume 55(Issue 7) pp:1893-1900
Publication Date(Web):1 April 2014
DOI:10.1016/j.polymer.2014.02.025
An effective method for fabrication of long range ordered micro- and nanostructures on surfaces is to control the interactive crystallisation of block copolymers. In this study, the influence of different initial mesophases of a double crystalline polyethylene-block-poly (ethylene oxide) (PE-b-PEO) diblock co-oligomer on the interactive crystallisation process was studied using synchrotron radiation X-ray diffraction (SAXS/WAXD), in situ optical microscopy and differential scanning calorimetric analysis (DSC). According to the applied annealing procedure, different PE-b-PEO initial mesophases, i.e., disordered, cylindrical and spherical, have been induced. In all cases, the subsequent PEO crystallisation disrupted these initial microdomains and transformed them into crystalline lamellar morphologies with the same long periods. However, the different initial mesophases significantly affected the PEO crystallisation kinetics due to different topological confinements. An initial disordered mesophase induced the highest PEO crystallisation rate because PEO nucleation and crystal growth were limited only by chain diffusion. For an initial spherical or cylindrical mesophase, decreased PEO crystallisation rates were observed. Here, the chain diffusion was decreased by the microdomain structure. For an initial cylindrical mesophase, the earlier formed PE crystals act as a template for the subsequent PEO crystallisation and, thus, increased the PEO crystallisation as compared to the spherical mesophase where the PE was amorphous. This study demonstrates that the topological confinement of the block copolymer's initial mesophase strongly influences the crystallisation kinetics and, thus, the structures formed at the surface of drop-casted films.
Co-reporter:Panpan Zhang, Ying Huang, Xin Lu, Siyu Zhang, Jingfeng Li, Gang Wei, and Zhiqiang Su
Langmuir 2014 Volume 30(Issue 29) pp:8980-8989
Publication Date(Web):2017-2-22
DOI:10.1021/la5024086
We demonstrated a facile one-step synthesis strategy for the preparation of a large-scale reduced graphene oxide multilayered film doped with gold nanoparticles (RGO/AuNP film) and applied this film as functional nanomaterials for electrochemistry and Raman detection applications. The related applications of the fabricated RGO/AuNP film in electrochemical nonenzymatic H2O2 biosensor, electrochemical oxygen reduction reaction (ORR), and surface-enhanced Raman scattering (SERS) detection were investigated. Electrochemical data indicate that the H2O2 biosensor fabricated by RGO/AuNP film shows a wide linear range, low limitation of detection, high selectivity, and long-term stability. In addition, it was proved that the created RGO/AuNP film also exhibits excellent ORR electrochemical catalysis performance. The created RGO/AuNP film, when serving as SERS biodetection platform, presents outstanding performances in detecting 4-aminothiophenol with an enhancement factor of approximately 5.6 × 105 as well as 2-thiouracil sensing with a low concentration to 1 μM. It is expected that this facile strategy for fabricating large-scale graphene film doped with metallic nanoparticles will spark inspirations in preparing functional nanomaterials and further extend their applications in drug delivery, wastewater purification, and bioenergy.
Co-reporter:Zhaofei Ouyang, Jingfeng Li, Jinhui Wang, Qian Li, Tongyang Ni, Xiaoyuan Zhang, Haixia Wang, Qing Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2013 vol. 1(Issue 18) pp:2415-2424
Publication Date(Web):18 Mar 2013
DOI:10.1039/C3TB20316F
We reported here the electrospinning preparation of polyurethane nanofibers filled with carbon nanotubes and silver nanoparticles (PU–MWCNT–AgNP) and the subsequent fabrication of a novel non-enzymatic amperometric biosensor for analytical determination of hydrogen peroxide. The morphologies of the as-spun PU–MWCNT–AgNP hybrid nanofibers were observed by scanning and transmission electron microscopy. The interaction between MWCNTs and AgNPs in the electrospun nanofibers was studied by differential scanning calorimetry and dynamic mechanical analysis. The cyclic voltammetry experiments indicate that PU–MWCNT–AgNP nanofiber modified electrodes have high electrocatalytic activity on hydrogen peroxide, and the chronoamperometry measurements illustrate that this electrospun sensor has high sensitivity for detecting hydrogen peroxide. Our study further confirms the remarkable synergistic effect of MWCNTs and AgNPs on the significant improvement of the conductivity of electrospun nanofibers and the electrocatalytic activity, as well as the sensitivity of the fabricated non-enzymatic sensor. Under an optimal experimental condition, the created biosensor for detecting hydrogen peroxide has a sensitivity of 160.6 μA mM−1 cm−2, a wide linear range from 0.5 to 30 mM and a detection limit of 18.6 μM (S/N = 3), which indicates that this novel and simple strategy for fabricating electrochemical sensor by an electrospinning technique has wide potential applications in bio-analysis and detection.
Co-reporter:Panpan Zhang, Xiaoyuan Zhang, Siyu Zhang, Xin Lu, Qing Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2013 vol. 1(Issue 47) pp:6525-6531
Publication Date(Web):17 Oct 2013
DOI:10.1039/C3TB21270J
We report here a facile one-pot green synthesis method to prepare a self-assembled membrane of reduced graphene oxide–gold nanoparticle (RGO–AuNP) nanohybrids at a liquid–air interface. The obtained sandwich-like multilayer RGO–AuNP hybrid membranes were characterized by atomic force microscopy, scanning electron microscopy, transmission electron microscopy, UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy, and the obtained results prove that GO and chloroauric acid (HAuCl4) were synchronously reduced by glucose successfully. In addition, the experimental data indicate that the self-assembly and formation of RGO–AuNP hybrid membranes are mainly governed by the Brownian motion and electrostatic interaction between RGO and AuNPs, and the encapsulation of AuNPs in the hybrid membrane can be easily adjusted by changing the concentration of HAuCl4. The created functional semi-transparent RGO–AuNP hybrid membranes are very stable in various organic and inorganic solvents, and can be used to fabricate a novel nonenzymatic amperometric biosensor of hydrogen peroxide (H2O2). The fabricated H2O2 biosensor reveals a wide linear range from 0.25 to 22.5 mM, low detection limit of 6.2 μM (S/N = 3), high selectivity, and long-term stability. It is expected that this one-pot green method for fabricating sandwich-like multilayer hybrid functional membranes has broad applications in biosensing, catalysis, and energy storage.
Co-reporter:Jingfeng Li, Jiaohong Zhao, Xiaojia Zhao, Klaus D. Jandt and Zhiqiang Su
RSC Advances 2013 vol. 3(Issue 43) pp:20254-20260
Publication Date(Web):21 Aug 2013
DOI:10.1039/C3RA43146K
Quantitative characterization of the complexation between proteins and electroneutral polymers is of great importance in biology and medicine science. However, the investigation of it has long been hindered due to the difficulties in characterization. And the few existing analysis models have various problems. In view of this, we focused on the complexation between proteins and electroneutral polymers in this work, and came up with a novel model analysis method to quantitatively characterize it. The mathematical model, based on the reversible complexing equilibrium among free proteins, free polymers and complexes of proteins with polymers, successfully associates the primary complexing parameters with the variation of the fluorescence intensities of the complexing system, so that one can quantitatively characterize the complexation of proteins with electroneutral water-soluble polymers in aqueous systems in situ, without destroying the dynamic equilibrium, which is more accurate. In this study, the complexation of bovine serum albumin (BSA) with poly(N-iso-propylacrylamide) (PNIPAM) is investigated as an example, and with the help of this method, numerous complexing parameters can be calculated accurately and rapidly. And by examining their variation with the increase of the mixing ratio (rmixing, molar ratio of PNIPAM to BSA), the complex interaction of proteins with electroneutral water-soluble polymers is further illuminated. Compared with traditional analysis methods, this method has the advantages of simplicity, accuracy and extensive application.
Co-reporter:Li Cao;Mu Dong;Anyang Zhang;Yong Liu;Weimin Yang;Xiaonong Chen
Polymer Engineering & Science 2013 Volume 53( Issue 12) pp:2674-2682
Publication Date(Web):
DOI:10.1002/pen.23515
Ultrafine fibers or fiber web is an attractive material for its high aspect ratio or porous structure which is welcomed in various applications. In this study, ultrafine fibers (5–10 μm) of styrene–acrylonitrile (SAN) copolymer/isotactic polypropylene (iPP) blends were produced by melt electrospinning, SAN acted as a polymeric nucleating agent (PNA) in iPP fibers. Wide-angle X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and polarized optical microscopy were used to investigate the morphologies and the crystal structures of SAN/iPP electrospun fibers. The results showed that SAN/iPP melt formed microfibers with different morphologies and crystallinities through electrostatic stretching. The morphological distribution of SAN in iPP fibers depended on the SAN content, and the distribution influenced its nucleating activity and the final crystal structure of SAN/iPP electrospun fibers. After annealing treatment, the molecular chains of iPP in the confined SAN/iPP microfibers disorientated and rearranged, leading to the formation of a mixture of α- and γ-crystal forms. The relative amount of the γ-crystal form depended on PNA's concentration, annealing temperature and annealing time. Melt electrospun iPP fibers prepared in this study were collected as fiber webs that can be used for protective clothing material, filtration media, reinforcement for composites, and so on. POLYM. ENG. SCI., 53:2674–2682, 2013. © 2013 Society of Plastics Engineers
Co-reporter:Gang Wei, Yue Zhang, Sascha Steckbeck, Zhiqiang Su and Zhuang Li
Journal of Materials Chemistry A 2012 vol. 22(Issue 33) pp:17190-17195
Publication Date(Web):03 Jul 2012
DOI:10.1039/C2JM32979D
Biomimetic synthesis is one of the facile strategies for creating novel nanostructured materials. Here we reported ferritin (Fr)-mediated biomimetic synthesis of FePt nanoparticles (NPs) on graphene nanosheets (GNs). GNs were noncovalently modified with 1-pyrenebutyric acid N-hydroxysuccinimide ester to provide binding sites for Fr molecules. The successful modification was demonstrated by X-ray photoelectron spectroscopy (XPS) and the formation of GN–Fr nanohybrids were identified with atomic force microscopy (AFM) and transmission electron microscopy (TEM). FePt NPs were synthesized by chemical reduction of metallic Fe2+ and PtCl62− that entered the core of Frs. The created GN–FePt nanohybrids exhibit multifunctions like high water-solubility, ferromagnetism, fluorescence, and enhanced electrocatalytic activity. The synthesized GN–FePt nanohybrids have potential applications in drug delivery, cell imaging, and biosensors.
Co-reporter:Zheng Yu;Jingfeng Li;Limin Yang;Yalin Yao;Xiaonong Chen
Journal of Applied Polymer Science 2012 Volume 123( Issue 2) pp:1079-1084
Publication Date(Web):
DOI:10.1002/app.34573
Abstract
Nano carboxylic acrylonitrile butadiene rubber latex-toughened-phenolic resins (XNBRL-PF) were prepared by in situ polymerization in this work. The influence of nano XNBRL on the microstructure and physical properties of modified PF resin was investigated. Impact test testified that the impact strength of XNBRL-PF was remarkably improved compared to pure PF and as the content of XNBRL increased to 10 wt %, the impact strength of the XNBRL-PF kept increasing. Scanning electron microscope analysis of the fracture surface of the XNBRL-PF indicated that the XNBRL were uniformly dispersed in the PF matrix, with diameters ranging from 200 to 400 nm. The results of Fourier transform infrared spectroscopy proved that chemical reaction occurred between XNBRL and PF matrix, which can greatly improve the interface interaction between rubber particles and PF matrix. Thermogravimetric analysis test showed that the incorporation of XNBRL can improve the thermostability of PF at low temperatures. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Cun Tian;Qing Zhou;Li Cao;Zhi-qiang Su;Xiao-nong Chen
Journal of Applied Polymer Science 2012 Volume 124( Issue 6) pp:5229-5235
Publication Date(Web):
DOI:10.1002/app.34149
Abstract
Polyurethane (PU) prepolymer was first prepared via introducing double bonds on-to the PU chains, and then polyurethane–poly (butyl methacrylate) (PU–PBMA) hybrid latex was prepared via miniemulsion polymerization. Transmission electron microscopy, Differential scanning calorimeter (DSC), Fourier transform infrared, and dynamic mechanical analysis were adopted to characterize the hybrid latex and its coating film. Both the coating property and the miscibility of PU–PBMA emulsion have been greatly improved through introducing double bonds into PU prepolymer. With an increase in the molecule weight of PU (MPU), the increase in the particle size of PU–PBMA emulsion was observed plus decreases in the stability of the hybrid latex and conversion of methacrylate. Besides, as MPU increased, the final dried coating film of the hybrid latex showed decreased water resistance, weakened miscibility, and improved mechanical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Qing Zhou;Li Cao;Qing Li;Yalin Yao;Zhaofei Ouyang;Xiaonong Chen
Journal of Applied Polymer Science 2012 Volume 125( Issue 5) pp:3695-3701
Publication Date(Web):
DOI:10.1002/app.36674
Abstract
The curing process of a typically formulated spray polyurea elastomer (SPUA) system has been thoroughly investigated with the help of a combined analysis of Fourier transform infrared spectroscopy, differential scanning calorimetry, and dynamic mechanical analysis. The evolvement of the microstructure and mechanical responses of the SPUA system during the curing process have been described in detail. The experimental results indicated that the fast curing property of SPUA, which mainly based on the reaction between the primary amine groups and the isocyanate groups, led to the formation of the unstable hard segments in the interphase. After the tack-free time, the residual isocyanate groups continued to react with the rest of the secondary amine groups of the chain extenders for several hours and caused the increase of the molecular weight of the hard segment in SPUA. Furthermore, during the curing process, the “disordered” hydrogen bond formed by one CO and one nearby NH (secondary amine) reconstructed to “ordered” bond, which contributed to the increase of the content of the hard segment and ultimately, improved the mechanical properties of the SPUA system greatly. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Shuxian Shi;Hao Wei;Xiaonong Chen
Journal of Applied Polymer Science 2010 Volume 117( Issue 6) pp:3308-3314
Publication Date(Web):
DOI:10.1002/app.30748
Abstract
The controlled formation of aragonite by simple method under ambient condition is a big challenge for biomaterial scientists. In this article, we took poly (N-vinyl pyrrolidone) (PVP) as an example to investigate the influence of water-soluble nonionic polymers on the polymorphs of CaCO3 via CO2 diffusion method under ambient pressure and temperature, and found that the existence of PVP molecules favors the formation of aragonite with rosette superstructure. A possible mechanism is proposed that nonionic polymers can be doped into amorphous calcium carbonate (ACC) particles and further participate in the transformation process from ACC to aragonite and then promotes the formation of rosette superstructure through parallel aggregation by crosslinking the aragonite nuclei. The experiments of CaCO3 crystallization in presence of poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA) confirmed the mechanism. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Siqi Zheng;Shuxian Shi;Yuzheng Xia;Qijiayu Wu;Xiaonong Chen
Journal of Applied Polymer Science 2010 Volume 118( Issue 2) pp:671-677
Publication Date(Web):
DOI:10.1002/app.32441
Abstract
A kind of thermo-sensitive macromonomer, styrene-terminated poly(N-isopropylacrylamide-butyl acrylate) [P(NIPAm-BA)] has been synthesized in this work. With the help of ultraviolet spectrum (UV), proton nuclear magnetic resonance (1H-NMR), potentiometric titration and dynamic light scattering (DLS), the molecular structure, thermo-sensitive characteristics, and micellization behaviors of this kind of macromonomer have been investigated. The obtained results demonstrate that, the molecular structure of thermo-sensitive macromonomer, including the content of comonomer unit on the backbones and the variety of terminal groups, has great influence on its low critical solution temperature (LCST) and critical micelle concentration (CMC). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Zhi-Qiang Su;Xiao-Nong Chen;Zhong-Zhen Yu ;Liang Zhang
Journal of Applied Polymer Science 2009 Volume 111( Issue 2) pp:786-793
Publication Date(Web):
DOI:10.1002/app.29098
Abstract
The morphological development of a special polymeric nucleating agent [acrylonitrile–styrene copolymer (SAN)] in the isotactic polypropylene (iPP) matrix in the process of injection molding has been investigated by means of wide-angle X-ray diffraction and scanning electron microscope. The current experimental results indicate that the shear field, in combination with the temperature gradient, has great influence on the morphological distribution of SAN in the process of injection molding. For injection-molded SAN/iPP specimens with higher SAN concentration (≥4%), SAN assembles to many microspheres and disperses uniformly in the isotropic core region; while from isotropic core region to oriented skin region, these SAN microspheres are gradually stretched into fibrils as a result of shear effect. On the contrary, for the specimens with lower SAN concentration (<4%), only microspheres can be observed in the core region and the skin region. At the same time, SAN has been proved to be a kind of special β-nucleating agent. The addition of SAN into iPP helps enhances the crystallinity and the content of β crystal form of injection-molded specimen. The morphology and the distribution of SAN in iPP matrix have great influence on the SAN's nucleating activity, which will ultimately affect the final crystalline structures of injection-molded specimens. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Mu Dong;Zhaoxia Guo;Jian Yu
Journal of Polymer Science Part B: Polymer Physics 2008 Volume 46( Issue 12) pp:1183-1192
Publication Date(Web):
DOI:10.1002/polb.21451
Abstract
Sodium benzoate (SB), a conventional nucleating agent of α-phase isotactic polypropylene (iPP) was discovered to induce the creation of β-phase iPP under certain crystalline conditions. Polarized optical microscopy (POM) and wide angle X-ray diffraction (WAXD) were carried out to verify the versatile nucleating activity of SB and investigate the influences of SB's content, isothermal crystallization temperature, and crystallization time on the formation of β-phase iPP. The current experimental results indicated that, under isothermal crystallization conditions, SB showed peculiar nucleating characteristics on inducing iPP crystallization which were different from those of the commercial β form nucleating agent (TMB-5). The content of β crystal form of iPP nucleated with SB (PP/SB) increased initially with the increase of crystallization temperature, nucleating agent (SB) percentage or crystallization time, reached a maximum value, and then decreased as the crystallization temperature, nucleating agent percentage or crystallization time further increased. While the content of β crystal form of iPP nucleated with TMB-5 (PP/TMB-5) showed a completely different changing pattern with the crystallization conditions. The obvious difference of the two kinds of nucleating agents on inducing iPP crystallization can be explained by the versatile nucleating ability of SB. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1183–1192, 2008
Co-reporter:Xiaoqing Yu, Zhenping Wang, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2017 - vol. 5(Issue 6) pp:NaN1142-1142
Publication Date(Web):2016/12/19
DOI:10.1039/C6TB02659A
By specifically binding with various inorganic nanomaterials through their functional groups or introducing special reactivity, the nanostructures and biofunctions of designed peptides can be enriched. This review provides a brief discussion on the design, composition, and biomedical applications of bioinspired peptide–inorganic nanomaterial hybrids. The attaching mechanisms of different peptide–inorganic nanomaterials are discussed from the viewpoint of the functional group, nanostructure, and conformational freedom. Particularly, the structures and functions of the obtained hybrids based on different nanomaterials are described in detail. In addition, we highlight some examples of self-assembled peptide–inorganic nanomaterial systems with relevance to biomedical applications, including biosensors, cell targeting, bioimaging, biomineralization, biocatalysts, and drug delivery. We also give a short outlook on the broad prospects of the fabrication and applications of peptide–inorganic nanomaterial hybrids.
Co-reporter:Mingfa Zhang, Xinne Zhao, Guanghua Zhang, Gang Wei and Zhiqiang Su
Journal of Materials Chemistry A 2017 - vol. 5(Issue 9) pp:NaN1711-1711
Publication Date(Web):2017/01/11
DOI:10.1039/C6TB03121H
Electrospinning represents a simple and effective strategy for fabricating nanofibrous structures and materials with large surface-to-volume ratios and desirable engineered properties. Thus, incorporating nanoscale building blocks (NBBs) like nanoparticles, graphene quantum dots, carbon nanotubes, and graphene into electrospun fibers has become one of the most attention-getting research topics in the field of biosensing. However, the dispersion behavior of NBBs in the nanofibers, the limited surface area of nanofibers and the insufficient immobilization sites for tested biomolecules still restrict the better performances and broader applications of the fabricated biosensors. In this review, we present a comprehensive survey of strategies that have been utilized to fabricate functional fibrous nanostructures for the amplification of the detection signals of nanostructure-based biosensors. In particular, from the perspective of design configuration, we systematically summarized recent advances in the electrospinning fabrication of hybrid polymer nanofibers decorated with functionalized NBBs. The strategies for promoting better dispersion of NBBs in electrospun nanofibers, including direct blending before electrospinning and in situ synthesis during electrospinning, are introduced in detail. In addition, some effective processing routes for increasing immobilization sites of tested biomolecules such as arrangement of NBBs and morphological processing of nanofibers are also presented. In addition, the suitability of electrospun nanostructures for biosensors, and the advantages and disadvantages of each method for improving the biosensing performance are also discussed.
Co-reporter:Panpan Zhang, Haixia Wang, Xiaoyuan Zhang, Wei Xu, Yang Li, Qing Li, Gang Wei and Zhiqiang Su
Biomaterials Science (2013-Present) 2015 - vol. 3(Issue 6) pp:NaN860-860
Publication Date(Web):2015/04/28
DOI:10.1039/C5BM00058K
Graphene and silver nanoparticles (AgNPs) are important building blocks for the synthesis of functional nanomaterials for bio-related applications. Here, we report a facile strategy to decorate AgNPs onto reduced graphene oxide (RGO) by the simultaneous reduction of silver ions and graphene oxide nanosheets within one system, and further to fabricate a dimension-adjustable RGO/AgNP multi-layered film by a thermal-driven self-assembly process. The structures of the fabricated RGO/AgNP hybrid films were identified by UV-visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy. The thickness of the fabricated RGO/AgNP film was further measured by scanning electron microscopy. The hydrophilicity of the RGO/AgNP films was tested by contact angle measurement. Antibacterial and cell culture experiments based on the fabricated RGO/AgNP films indicate that this kind of hybrid film exhibits excellent antibacterial activity and high biocompatibility. A potential antibacterial mechanism of the fabricated RGO/AgNP hybrid film was proposed.
Co-reporter:Jinhui Wang, Haixia Wang, Yizhu Wang, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2014 - vol. 2(Issue 42) pp:NaN7368-7368
Publication Date(Web):2014/09/08
DOI:10.1039/C4TB01324G
Layer-by-layer (LBL) assembly is a simple and effective method for the fabrication of a three-dimensional (3D) scaffold for nanotechnological and biomedical applications. Herein, a novel 3D scaffold based on an alternate LBL assembly of graphene oxide (GO) nanosheets and fibrinogen nanofibers (Fg NFs) on a silicon substrate was fabricated and utilized to create a 3D hydroxyapatite (HA) scaffold by biomimetic mineralization in 1.5× simulated body fluid for different nucleation periods. The obtained 3D (GO–NF)n–HA scaffold was characterized using atomic force microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results demonstrate that the Fg NFs could promote the nucleation and growth of HA crystals along the axis. The 3D (GO–NF)10–HA scaffold composed of 10 layers of GO alternating with 10 layers of NFs was successfully created by LBL assembly and subsequent biomimetic mineralization. The effects of the created 3D (GO–NF)10–HA scaffolds on the adhesion, morphology, and proliferation of L-929 cells were investigated. The in vitro cell culture indicates that the 3D (GO–NF)10–HA scaffold has a higher proliferation ability and better cytocompatibility than the other control samples.
Co-reporter:Yang Li, Xiaojia Zhao, Panpan Zhang, Jing Ning, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2015 - vol. 3(Issue 16) pp:NaN4133-4133
Publication Date(Web):2015/03/13
DOI:10.1039/C5TC00196J
We demonstrated here a facile approach to produce a large-scale reduced graphene oxide–silver nanoparticle (RGO–AgNP) hybrid film, and further explored its application as a highly active surface-enhanced Raman scattering (SERS) substrate. The RGO–AgNP nanohybrids were firstly synthesized by reducing graphene oxide (GO) and Ag+ cations with sodium citrate, and the RGO–AgNP hybrid film was then fabricated by evaporating the RGO–AgNP nanohybrids solution and harvesting the film formed at the air–liquid interface with a solid substrate. Two probe molecules, Rhodamine 6G (R6G) and melamine (MA), were chosen to evaluate the enhancement performance of the fabricated SERS-active substrate. Our results indicated that this RGO–AgNP hybrid film-based SERS-active substrate presents outstanding performances for detecting R6G with an enhancement factor of 2.3 × 106 and a detection limit of approximately 1.0 × 10−12 M. In addition, this SERS substrate shows excellent ability to recognize MA molecules with a detection limit of approximately 1.0 × 10−7 M.
Co-reporter:Gang Wei, Yue Zhang, Sascha Steckbeck, Zhiqiang Su and Zhuang Li
Journal of Materials Chemistry A 2012 - vol. 22(Issue 33) pp:NaN17195-17195
Publication Date(Web):2012/07/03
DOI:10.1039/C2JM32979D
Biomimetic synthesis is one of the facile strategies for creating novel nanostructured materials. Here we reported ferritin (Fr)-mediated biomimetic synthesis of FePt nanoparticles (NPs) on graphene nanosheets (GNs). GNs were noncovalently modified with 1-pyrenebutyric acid N-hydroxysuccinimide ester to provide binding sites for Fr molecules. The successful modification was demonstrated by X-ray photoelectron spectroscopy (XPS) and the formation of GN–Fr nanohybrids were identified with atomic force microscopy (AFM) and transmission electron microscopy (TEM). FePt NPs were synthesized by chemical reduction of metallic Fe2+ and PtCl62− that entered the core of Frs. The created GN–FePt nanohybrids exhibit multifunctions like high water-solubility, ferromagnetism, fluorescence, and enhanced electrocatalytic activity. The synthesized GN–FePt nanohybrids have potential applications in drug delivery, cell imaging, and biosensors.
Co-reporter:Haixia Wang, Dianming Sun, Nana Zhao, Xinchao Yang, Yuzhou Shi, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2014 - vol. 2(Issue 10) pp:NaN1370-1370
Publication Date(Web):2013/12/06
DOI:10.1039/C3TB21538E
We report the covalent interaction mediated assembly of thermo-sensitive polymer nanoparticles (PNPs) on functionalized graphene oxide (GO) nanosheets to create novel GO–PNP hybrids for drug delivery. To this end, thermo-sensitive PNPs with an average diameter of about 50 ± 12 nm were first synthesized with the free radical polymerization reaction, and GO nanosheets were noncovalently modified with a bifunctional linker to provide reactive sites for the binding of PNPs. Finally, GO–PNP hybrids were successfully synthesized by the covalent interaction mediated assembly of PNPs on GO nanosheets. Multi-characterization techniques were utilized to identify the formation of PNPs, the modification of GO nanosheets, and the formation of GO–PNP hybrids. Cell culture experiment with the mouse osteoblast-like MC3T3-E1 cells indicates that the synthesized GO–PNP hybrids have satisfactory biocompatibility. The loading efficiency of drug molecules (Adriamycin, ADR) with GO–PNP (∼87%) is close to that with GO (∼91%), but significantly higher than that with PNPs (∼46%). The release efficiency of GO–PNP hybrids with the highest surface coverage of PNPs (∼85 PNPs per μm2) is about 22%, which is very close to that of PNPs (∼25%) and significantly higher than that of GO (∼11%). Our study indicates that this thermo-sensitive GO–PNP hybrid, when considering the drug loading and release comprehensively, has better performance than both PNPs and GO and thus can be used as a novel nanocarrier for temperature-controllable drug release. The GO–PNP hybrids with and without ADR were applied to kill cancer cells in vitro and the result shows that the GO–PNP hybrid with ADR has an obvious effect on killing cancer cells, and its performance is obviously better than both GO and PNPs. It is expected that this new hybrid material based on GO and PNPs will have great potential for in vivo applications such as to kill target cancer cells by modifying with specific antibodies.
Co-reporter:Panpan Zhang, Xiaoyuan Zhang, Siyu Zhang, Xin Lu, Qing Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2013 - vol. 1(Issue 47) pp:NaN6531-6531
Publication Date(Web):2013/10/17
DOI:10.1039/C3TB21270J
We report here a facile one-pot green synthesis method to prepare a self-assembled membrane of reduced graphene oxide–gold nanoparticle (RGO–AuNP) nanohybrids at a liquid–air interface. The obtained sandwich-like multilayer RGO–AuNP hybrid membranes were characterized by atomic force microscopy, scanning electron microscopy, transmission electron microscopy, UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy, and the obtained results prove that GO and chloroauric acid (HAuCl4) were synchronously reduced by glucose successfully. In addition, the experimental data indicate that the self-assembly and formation of RGO–AuNP hybrid membranes are mainly governed by the Brownian motion and electrostatic interaction between RGO and AuNPs, and the encapsulation of AuNPs in the hybrid membrane can be easily adjusted by changing the concentration of HAuCl4. The created functional semi-transparent RGO–AuNP hybrid membranes are very stable in various organic and inorganic solvents, and can be used to fabricate a novel nonenzymatic amperometric biosensor of hydrogen peroxide (H2O2). The fabricated H2O2 biosensor reveals a wide linear range from 0.25 to 22.5 mM, low detection limit of 6.2 μM (S/N = 3), high selectivity, and long-term stability. It is expected that this one-pot green method for fabricating sandwich-like multilayer hybrid functional membranes has broad applications in biosensing, catalysis, and energy storage.
Co-reporter:Zhaofei Ouyang, Jingfeng Li, Jinhui Wang, Qian Li, Tongyang Ni, Xiaoyuan Zhang, Haixia Wang, Qing Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2013 - vol. 1(Issue 18) pp:NaN2424-2424
Publication Date(Web):2013/03/18
DOI:10.1039/C3TB20316F
We reported here the electrospinning preparation of polyurethane nanofibers filled with carbon nanotubes and silver nanoparticles (PU–MWCNT–AgNP) and the subsequent fabrication of a novel non-enzymatic amperometric biosensor for analytical determination of hydrogen peroxide. The morphologies of the as-spun PU–MWCNT–AgNP hybrid nanofibers were observed by scanning and transmission electron microscopy. The interaction between MWCNTs and AgNPs in the electrospun nanofibers was studied by differential scanning calorimetry and dynamic mechanical analysis. The cyclic voltammetry experiments indicate that PU–MWCNT–AgNP nanofiber modified electrodes have high electrocatalytic activity on hydrogen peroxide, and the chronoamperometry measurements illustrate that this electrospun sensor has high sensitivity for detecting hydrogen peroxide. Our study further confirms the remarkable synergistic effect of MWCNTs and AgNPs on the significant improvement of the conductivity of electrospun nanofibers and the electrocatalytic activity, as well as the sensitivity of the fabricated non-enzymatic sensor. Under an optimal experimental condition, the created biosensor for detecting hydrogen peroxide has a sensitivity of 160.6 μA mM−1 cm−2, a wide linear range from 0.5 to 30 mM and a detection limit of 18.6 μM (S/N = 3), which indicates that this novel and simple strategy for fabricating electrochemical sensor by an electrospinning technique has wide potential applications in bio-analysis and detection.
Co-reporter:Panpan Zhang, Xinne Zhao, Yuanchun Ji, Zhaofei Ouyang, Xin Wen, Jingfeng Li, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2015 - vol. 3(Issue 12) pp:NaN2496-2496
Publication Date(Web):2015/02/02
DOI:10.1039/C4TB02092H
Graphene quantum dots (GQDs) have become increasingly important for applications in energy materials, optical devices and biosensors. Here we report a facile technique to fabricate a nanofibrous membrane of GQDs by electrospinning water-soluble GQDs with polyvinyl alcohol (PVA) directly. The structure and fluorescence properties of the fabricated PVA/GQD nanofibrous membrane were investigated using scanning and transmission electron microscopy, and fluorescence microscopy. It was found that the electrospun PVA/GQD nanofibrous membrane has a three-dimensional structure with a high surface area to volume ratio, which is beneficial for the adsorption of electrolytes and the diffusion of reactants. For the first time, the created PVA/GQD nanofibrous membrane was utilized to fabricate dual-purpose fluorescent and electrochemical biosensors for highly sensitive determination of hydrogen peroxide (H2O2) and glucose. The experimental results indicated that the fluorescence intensity of the nanofibrous membrane decreased linearly with increasing H2O2 concentration, because the addition of H2O2 leads to fluorescence quenching of the GQDs, which endows the fabricated nanofibrous membrane with fluorescence activity. Besides, after binding glucose oxidase onto the created nanofibrous membrane, the fabricated nanofibrous membrane showed high sensitivity and selectivity for glucose detection. In addition, the PVA/GQD nanofibrous membrane can also be directly electrospun onto an electrode for electrochemical detection of H2O2. This novel nanofibrous membrane exhibits excellent catalytic performance and fluorescence activity, and therefore has potential applications for the highly stable, sensitive, and selective detection of H2O2 and glucose.
Co-reporter:Panpan Zhang, Xueyi Lu, Ying Huang, Junwen Deng, Lin Zhang, Fei Ding, Zhiqiang Su, Gang Wei and Oliver G. Schmidt
Journal of Materials Chemistry A 2015 - vol. 3(Issue 28) pp:NaN14566-14566
Publication Date(Web):2015/06/15
DOI:10.1039/C5TA02945G
We demonstrate here a facile one-step hydrothermal synthesis to prepare molybdenum disulfide nanosheets decorated with gold nanoparticles (MoS2/AuNPs) for rechargeable Li–O2 batteries. The fabricated Li–O2 battery exhibits enhanced specific capacity and cycle efficiency, which are ascribed to the two-dimensional structure of MoS2/AuNP nanohybrids and the synergistic catalytic effects of both MoS2 nanosheets and AuNPs.
Co-reporter:Keheng Li, Wei Liu, Yao Ni, Dapeng Li, Dongmei Lin, Zhiqiang Su and Gang Wei
Journal of Materials Chemistry A 2017 - vol. 5(Issue 25) pp:NaN4826-4826
Publication Date(Web):2017/05/12
DOI:10.1039/C7TB01073G
Graphene quantum dots (GQDs) have generated enormous excitement because of their superiority in chemical inertness, biocompatibility and low toxicity. Due to quantum confinement and edge effects, GQDs have excellent properties, attracting extensive attention from scientists in the fields of chemistry, physics, materials science, biology, and other interdisciplinary sciences. In this review, we aim to present a comprehensive view on the synthesis of GQDs for biological applications. We highlight potential methods like acid oxidation, hydrothermal and solvothermal reactions, microwave-assisted methods, electrochemical oxidation, as well as pyrolysis and carbonization for the successful preparation of GQDs. Meanwhile, four representative types of biomedical application based on GQDs, bioimaging, biosensing, drug delivery, and antimicrobial materials, are introduced and discussed in detail. This work will be very useful for quickly gaining knowledge and experience for synthesizing various GQDs, and developing advanced strategies for creating novel functional GQD-based nanomaterials for further applications in biomedicine, materials science, analytical science, and optical nanodevices.
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