纳米银/半胱氨酸修饰葡萄糖生物传感器的研究

Study of glucose biosensor based on silver nanoparticles/L-cysteine modified gold electrode

为优化电流型生物传感器的性能，采用相转移法结合超声波法制备纳米银溶胶，并用透射电镜对其粒径和形态进行了表征。将纳米银／半胱氨酸与葡萄糖氧化酶（GOD）共同修饰在电极表面制成酶电极。结果表明：制备的纳米银粒子近似球形，平均直径为6．27nm；酶电极的线性响应范围为5.0×10^-5－1.5×10^-3mol／L；检出限为7.14×10^-6mol／L（S／N=3）；响应时间小于5s。4℃保存30d，该电极仍有83.7％的初始响应电流，重复性和稳定性良好。

The preparation of glucose oxidase electrode immobilized on the carrier composing of sliver nanoparticles/L-cysteine is studied to optimize the current biosensor. Silver nanoparticles are prepared by reduction of AgNO3 with NaBH4. The particle diameter and morphology of silver nanoparticles are characterized by transmission electron microscopy methods. Experimental results show that the silver nanoparticles are 6.27 nm in diameter and approximately sphericity in shape. The linear response range of the enzyme electrode is 5.0×10^-5-1.5×10^-3mol/L with the detection limits of 7.14×10^-6mol/L（S/N=3） and a stable response time is less than 5s. The biosensor has the advantages of good repeatability and stability, remaining 83.7% of its original current value after a month at 4℃.