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 μM with the calculated detection limit of 0.088 μM (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.