A targeted detection of gastric cancer cells is achieved by combining the giant magnetoimpedance (GMI)-based biosensing system and RGD-4C peptide coupled, chitosan covered superparamagnetic iron oxide particles (RGD-Fe3O4@chitosan). The micro-patterned GMI sensor for targeted detection is made of Co-based ribbon and fabricated by micro electromechanical system (MEMS) technology. Functionalized nanoparticles were designed by coating Fe3O4 with chitosan and conjugating with RGD-4C peptides. The targeted cells were trickled down into the detection area of the system. The detection of each sample is carried out in ten-fold manner and average value is taken as the final result. This system can identify the differences between targeted cells and non-targeted cells. It is of considerable interest due to its potential application in the biomedical field of various specific detections.

NiFe single layered films and NiFe/Cu/NiFe sandwich films are fabricated by MEMS technology to investigate the influence of sputtering parameters and sample size on the giant magnetoimpedance (GMI) effect in thin films. Optimal sputtering parameters are selected based on the GMI ratio and magnetization curves of the different single layered thin films. The maximum GMI ratio of 15% is observed in NiFe/Cu/NiFe sandwich film with a length of 4 mm, the NiFe layer width of 100 μm and the Cu layer width of 40 μm. The result shows that GMI effect of thin films can be significantly improved by proper sputtering parameters, well-designed sample size and sandwich structure.