Catechol Biosensor Based on ZnS:Ni/ZnS Quantums Dots and Laccase Modified Glassy Carbon Electrode

In this study, a simple and sensitive electrochemical analytical method is developed for detection of catechol based on laccase and ZnS:Ni/ZnS quantum dots with core/shell structure modified glassy carbon electrode using cyclic voltammetry. The proposed biosensor showed an excellent catalytic activity toward the reduction of catechol, which exhibited a linear response to the concentrations ranging from 0.1 to 100 μmol · L−1 with a low detection limit of 35 nmol · L−1 for catechol (S/N = 3). The reproducibility, interference and stability of the measurements were also favorable with a high retention rate of 95.31% of the peak current after 30 days. Moreover, this novel method has been successfully applied to determination of catechol in real water with satisfactory recoveries. The resulting biosensor will provide important improvements for electrochemical biosensors in application for environment.