Carbon-doped h-BN for the enhanced electrochemical determination of dopamine

Abstract Since dopamine (DA) is one of the central neurotransmitters and plays an important role in the human metabolism, its accurate detection is crucial for the diagnosis of DA-linked diseases. Herein, we demonstrated a novel electrochemical sensor for DA detection based on carbon-doped hexagonal boron nitrogen (C-hBN). C-hBN was prepared via a thermal polymerization process using melamine borate as a precursor. The successful C-doping was evidenced by fourier transform infrared (FTIR), photoluminescent (PL) and x-ray photoelectron spectroscopy (XPS). The carbon-doping can increase reactive sites and facilitate electrons transfer in h-BN, which was confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The C-hBN modified glassy carbon electrode (C-hBN/GCE) exhibited the enhanced electrocatalytic activity toward DA redox, whose CV peak current is 2.8 and 4.3 times higher than those of pure h-BN modified and bare GCEs, respectively. Based on CV method, the C-hBN/GCE presented a low detection limit of 5.8 nM (S/N = 3) and a sensitivity of 2037 µA•mM•cm−2. The linear response ranges were over the DA concentrations of 0.01–40 µM and 40–300 µM, respectively. In addition, the sensor was applied to detect DA in real samples including human serum and urine, and satisfactory results were achieved. The results suggested that the defect-engineered h-BN holds great potential for the development of electroanalytical devices with high-performance.