Electrochemical Determination of Ascorbic Acid Based on AgNPs/PVP-Modified Glassy Carbon Electrode

摘要

The electrochemical determination of ascorbic acid was carried out at the surface of glassy carbon electrode (GCE) modified by silver nanoparticles (AgNPs):Polyvinylpyrrolidone (PVP). Nano- composite was evaluated by fourier transform infrared spectro- scopy, zeta potential, and X-ray diffraction. Also, the surface morphologies of the developed electrode were investigated by scanning electron microscopy, and profilometer. The electro- chemical performance of AgNPs/PVP/GCE was studied with cyclic voltammetry and electrochemical impedance spectro- scopy measurements. The electrochemical studies demon- strated that the electrode had a large surface. Compared with the bare GCE, PVP/GCE, and AgNPs/GCE, the AgNPs/PVP- modified GCE showed excellent performance for the electro- chemical determination of ascorbic acid. At the optimized conditions of differential pulse voltammetry in pH 6.0 of phosphate buffer solution, the modified electrode allowed the determination of ascorbic acid on a potential of 0.54 V vs. Ag/ AgCl. Under optimized conditions, the low detection limit of 0.047 μM and working range of 0.2-1200 μM were obtained at the AgNPs/PVP/GCE. The AgNPs/PVP/GCE allowed to obtain highest peak current values at low concentrations. Moreover, the fabricated electrode also exhibited good repeatability, reproducibility, and stability. The developed electrode was successfully enforced for the analysis of ascorbic acid in banana, kiwi fruit, mango, and pineapple.