基于GMR效应的新型生物传感器研究

制备出了结构为Ta/NiFe/CoFe/Cu/CoFe/MnIr/Ta,磁阻变化达9.2%的GMR自旋阀传感器,并用该种传感器对浓度为200μg/mL、直径2μm的生物免疫磁球溶液进行了检测。实验结果表明,该生物传感器可以对被测生物免疫磁球溶液产生平均350μV的电压输出信号,随着磁球溶液的继续增加,电压输出信号可以达到最大值450μV。除去背景干扰信号的影响,由磁球产生的有效电压输出信号为300μV。此外,交流励磁场的频率的增加也会使输出电压信号减小。

Study of a Novel Biosensor Based on GMR Effect

GMR Spin-Valve biosensors with the structure of Ta/NiFe/CoFe/Cu/CoFe/MnIr/Ta and MR 9.2% were prepared and used to detect the magnetically labeled molecules.In the detection of the biomoleculars(200 μg/mL) with the diameter of 2 μm,average signal of about 350 μV was obtained,and increased with the accession of the molecules,finally up to 450 μV.Considering the effect of background signal,the output of the magnetic molecules is about 300 μV.In addition,with the decrease of the applied frequency,the signal descends dramatically.