基于壳聚糖-纳米金/纳米普鲁士蓝/L-半胱氨酸修饰的葡萄糖传感器的研究

Glucose Biosensor Based on Chitosan-nano Gold/nano-Prussian Blue/L-cysteine Modified Gold Electrode

在金电极表面修饰带正电荷的L-半胱氨酸,再利用静电吸附作用固定纳米普鲁士蓝(nano-PB),然后利用壳聚糖-纳米金复合膜将葡萄糖氧化酶(GOD)固定于修饰电极表面,制成新型的葡萄糖传感器.通过交流阻抗技术,循环伏安法和计时电流法考察了电极的电化学特性.在优化的实验条件下,该传感器在葡萄糖浓度为3.0×10-6～1.0×10-3mol/L范围内有线性响应,检测下限为1.6×10-6mol/L.此外该传感器具有响应快、稳定性好和选择性良好的特点,能有效排除常见干扰物质如抗坏血酸、尿酸等对测定的影响.

A novel glucose biosensor has been presented in this paper. First, L-cysteine was immobilized onto a gold electrode to form a positively charged surface, then nano-Prussian blue was assembled on the modified surface as an electron transfer mediator. Finally, the hybrid film of chitosan-nano gold and glucose oxidase （GOD） was immobilized on the electrode to fabricate the proposed biosensor. The modifying process was characterized by electrochemical impedance spectroscopy （EIS）, cyclic voltammetry （CV） and transmission electron microscopy （TEM）. And the effects of applied potential and pH on the response currents were also investigated. Under optimal conditions, the resulting biosensor displayed a rapid response to glucose and the linear range of the biosensor was from 3.0×10^-6 to 1.0×10^-3 mol/L with a detection limit of 1.6× 10^-6 mol/L （S/N=3）. Moreover, the interferents influencing the proposed biosensor were researched in detail, and the biosensor possessed excellent selectivity and good stability.