Highly Sensitive and Selective Dopamine Detection Utilizing Nitrogen-Doped Mesoporous Carbon Prepared by a Molten...

Nitrogen-doped mesoporous carbons (N-MCs) are promising materials for electrochemical sensors or biosensors. However, facile and effective methods for the preparation of N-MCs for electrochemical detection of dopamine (DA) are required. A molten-glucose-assisted hard-template approach has been developed to synthesize N-MC materials by in situ introduction of nitrogen precursors, including ethylenediaminetetraacetic acid disodium salt (EDTA), dicyandiamide, and melamine. The combined characterization of X-ray diffraction (XRD), N₂ sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) indicate the successful preparation of N-MC materials. Most importantly, after detailed examination by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), N-MC obtained by using melamine as precursor (designated as N-MC-MA) displays good catalytic activity for electrochemical oxidation of DA. The N-MC-MA-based DA sensor shows a linear range from 0.2-8 μm with a detection limit of 0.05 μm in the presence of ascorbic acid (AA) and uric acid (UA), thus showing excellent sensitivity and selectivity for electrochemical DA detection.