自组装L-半胱氨酸修饰金电极检测对硝基苯酚

Self-assembled L-cysteine Modified Gold Electrode for Nitro-phenol Detection

制备了L-半胱氨酸自组装膜修饰的金电极,利用循环伏安法和差示脉冲伏安法研究了对硝基苯酚在该L-半胱氨酸自组装膜上的电化学行为,实验结果表明：相比于裸金电极,硝基苯酚在L-半胱氨酸自组装膜修饰的金电极上具有更高的电化学响应信号,这是由于L-半胱氨酸和对硝基苯酚之间存在氢键的作用,使得对硝基苯酚更容易聚集在电极表面。在最优实验条件下,该修饰电极在对硝基苯酚0~12.5μmol·L-1浓度范围内具有良好的线性关系,检出限为0.0295μmol·L-1（信噪比为3）;加标回收实验的回收率在95.51%至102.72%之间。

A kind of electrochemical sensor（L-Cys / Au） has been constructed by the formation of self-assembly of monolayer of L-cysteine on gold electrode. Here, we studied the electrochemical behavior of nitro phenol on the modified electrode by the methods of cyclic voltammetry（CV） and differential pulse（DPV）. The L-cysteine modified gold electrode showed higher voltammetric response, when compared to the gold electrode. It is attributed to the hydrogen bonding between L-cysteine and nitro-phenol. The nitro-phenol is vulnerably absorbed to the monolayer of L-cysteine.The result show that the assembled L-cysteine films voltammetric response is liner over the 0~12.5μmol·L-1ranges with the detectin limit of 0.0295μmol·L-1（D=3N/S）. The relative standard deviation（RSD） of less than 5% and the recovery of water sample is between 95.51% and 102.72%.