Au—Ni／酪氨酸酶修饰生物传感器检定BPA

将镍金材料结合壳聚糖修饰于玻碳电极表面形成复合膜，酪氨酸酶（Tyr）借助NHS～EDC联酶法修饰于复合膜上，制备了一种新型的酪氨酸酶修饰电极。以循环伏安法和电化学阻抗谱实验研究了修饰电极的电化学性能。由于复合材料良好的生物相容性和高电导特性，联酶法保持了酶活性和稳定性，该传感器对双酚A（BPA）具有良好的电化学响应。在最佳实验条件下，该传感器对双酚A的检测范围为：4．0×10^-8～5．0×10^-6mol／L，检测限为1.0×10^-8mol／L（信噪比=3）。该传感器具有良好的性能，重现性，稳定性。

Determination of BPA using Au-Ni/tyrosinase modified biosensor

A bisphenol A （BPA） biosensor was fabricated by immobilizing tyrosinase using a NHS-EDC method on the surface of glassy carbon electrode（GCE） modified with composite material of Au-Ni and chitosan. Tyrosinase can be immobilized on the surface of the electrode by NHS-EDC method. The composite film can keep the bioactivity of tyrosinase, possess excellent inherent conductivity and enhance the electron transfer rate and showed good electrocatalytic activity for the electrooxidation of BPA. Various electrochemical methods such as cyclic vohammetry, ac impedance method, difference pulse vohammetry, etc were used to characterize the sensor. The biosensor showed good electrochemical response to BPA. Under the optimum, the response current of the modified electrode was proportional to BPA concentration in the range from 4.0×10^-8- 5.0×10^-6 mol/L, and the detection limit of this method was 1.0×10^-8mol/L（S/N= 3）. The proposed method showed good electrochemical characteristics, stability and reproducibility.