Electrochemical determination of malachite green at graphene quantum dots-gold nanoparticles multilayers-modified glassy carbon electrode

摘要

A graphene quantum dots-gold nanoparticles-modified glassy carbon electrode was used to investigate the electrochemical behaviors of malachite green (MG). Cyclic voltammetry curves of MG at the modified electrode exhibited a pair of quasi-reversible adsorption-controlled redox peaks at 0.502 V (E _(pa)) and 0.446 V (E _(pc)) in a 0.05 mol L~(-1) H_2SO _4 solution. Under the optimal conditions, by using differential pulse voltammetry as the detection method, a linear relationship was obtained between the oxidation peak current and the MG concentration in the range of 4.0 × 10~(-7) to 1.0 × 10~(-5) mol L~(-1) with the detection limit as 1.0 × 10-7 mol L~(-1) (signal-to-noise ratio of 3). The modified electrode was applied in the determination of MG in fish samples, and the results were satisfactory with recoveries from 96.25 to 98.00 %. Furthermore, the modified electrode showed very good reproducibility and stability.