Electrochemical sensor based on nitrogen-fluorine double doped graphene composite for dopamine detection

Abstract

Metal-free catalysts with low cost and long - term stability are considered as the most promising electrocatalysts. Nitrogen-fluorine double doped graphene (NFG) was prepared by hydrothermal method which includes the reduction of graphene oxide by triethylamine trihydrofluorate as a novel dopamine (DA) electrochemical sensor. The morphologies and structures of GO and NFG were characterized via scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectra and BET. Cyclic voltammetry, and differential pulse voltammetry were used to investigate the electrochemical behavior of DA on the NFG/glassy carbon electrode (GCE). Impressively, all the fluorine in NFG is in the form of carbon-fluorine semi-ionic bonds. Based on these characteristics, the prepared nitrofl-doped graphene showed high performance in the electrochemical detection of DA. In the ranges of 1–50 μM, the peak current exhibited an excellent linear relationship with DA concentration and the detection limit was 0.3 μM. The proposed sensor has high sensitivity, low-detection limit, and a wide linear range. Notably, the adsorption of H+ by the carbon-fluorine semi-ionic bond accelerates the oxidation of DA. The synergistic effect between N, F and rGO affects the oxidation of DA, which is confirmed by the calculation of density functional theory (DFT).