自组装L-半胱氨酸修饰金电极检测对硝基苯酚

摘要

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-1 ranges 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%.%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。