Study On GMR Biosensor Integrated With Microchannel

This paper focuses on the study of GMR biosensor, which can detect magneticallylabeled biological analyte and therefore can be used in the field of disease diagnosis. We useComsol software to calculate the magnetic field of micro-beads magnetized by perpendicularmagnetic field, to study the influence of orientation of external magnetic field, position ofmagnetic particles and aggregation of magnetic particles on signal of GMR-based biosensor.Simulation results show that the response of sensor would be reduced by the tilt of externalfield, the deviation of the position of particles from the central areas of the sensor strip, andthe aggregation of particles. Consequently, to measure the magnetic particles quantitatively,efforts must be made to make the external magnetic field perpendicular to the sensor surface,and keep the tilt angle unchanged during the process of measurement; put the magneticparticles at the central areas of the sensor strip; avoid the magnetic particles aggregation.we fabricate GMR sensor, and then employ this sensor to detect magnetic micro-beadswhich are bound on the sensor surface. Currently, There are very few research groups whichwork on the integration of GMR sensor with micro-fluidic system and the detection offlowing magnetic beads. We test ferrofluid of different concentrations. Experimental resultsshow that, GMR sensor can not only detect the existence of ferrofluid, but also determine theconcentration of ferrofluid based on the response of GMR sensor.