基于氰化物对辣根过氧化物酶的抑制作用测定氰化物的研究

Study of the Determination of Cyanide Based on the Inhibition of Cyanide to the Horseradish Peroxidase

基于氰化物对辣根过氧化物酶(HRP)的抑制作用,将辣根过氧化物酶电极用于水中的微量氰化物的测定。酶电极制作中,先在金电极表面自组装一层半胱胺单层膜,再用戊二醛交联HRP。采用这种酶固定化方法,电极在6.0×10-5～4×10-3mol/LH2O2的浓度范围呈线性关系。探讨了工作电位、介体浓度、pH值、底物浓度等实验条件对酶电极性能及抑制过程中响应电流的影响,考察了电极的重现性、干扰及使用寿命。电极检测氰化物的线性范围为0.3～20μg/mL,检出限为100ng/mL,将电极用于水中CN-回收率的测定,结果良好。

Based on the inhibition of cyanide to the horseradish peroxidase(HRP), the HRP electrode has been used in the determination of cyanide in water. For the fabrication of HRP electrode, cysteamine was first self-assembled onto the surface of the gold electrode, and then HRP was immobilized onto the electrode through glutaraldehyde. Using this kind of immobilization method, the electrode exhibitsed a linear response for (H_(2)O_2)ranged from 6.0×10^(-5) to 4×10^(-3) mol/L .The effects of experimental conditions such as applied potential, mediator concentration, pH, substrate concentration on the electrode performance and response current in the inhibition were discussed. The reproducibility, interferences and lifetime of the electrode were also tested. The linear range of the detection of the electrode for cyanide was from 0.3 μg/mL to 20 μg/mL, with the detection limit of 100 ng/mL. The electrode was applied to the determination of cyanide in water with satisfactory results.