Detection of catechin in Chinese green teas at N-doped carbon-modified electrode

Herein, we present a simple and facile synthesis strategy of porous N-doped graphene (N-Gr) using a facile one-step pyrolysis method. The as-prepared N-Gr was characterized by power X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. N-Gr-modified glassy carbon electrode exhibited a lower overpotential and the higher redox peak currents for catechin during the electrochemical reaction of catechin. At the N-Gr-modified electrode, the redox process of catechin was almost reversible and displayed an adsorption-controlled redox process with a fast electron transfer rate. The linear responses of the sensor for catechin have been obtained by the differential pulse voltammetry in the range from 1.0 to 30 mu M with the calculated detection limit of 0.088 mu M (S/N = 3). The real application of catechin in Chinese green tea samples with excellent performance such as long-term stability and good reproducibility was successfully achieved.