Electrochemical sensor for amino acids based on gold nanoparticles/macroporous carbon composites modified glassy carbon electrode

摘要

Gold nanoparticles/macroporous carbon (GNPs-MPC) composites were simply fabricated by electrodepositing GNPs film on MPC using cyclic voltammetry (CV). The prepared composites were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS) and X-ray diffraction (XRD). Glassy carbon electrode (GCE) modified with GNPs-MPC was used as electrochemical sensor of L-tryptophane (L-Trp) and L-tyrosine (L-Tyr) for the first time. In 0.1 M PBS (pH = 7.4), the GNPs-MPC/GCE exhibited satisfactory electrocatalytic activity by significantly decreasing the oxidation potentials and increasing the peak currents of the oxidation of L-Trp and L-Tyr when compared with those modified electrodes. More importantly, the present electrode gave a wide linear range from 1.0x10~(-5)M to 1.0x10~(-3) M, 5.0x10~(-6) M to 1.0 x 10~(-3) M, a very low detection limit of 2.4x10~(-8) M, 7.4x10~(-8) M and a high sensitivity of 41 lAmM~(-1), 13 lAmM~(-1) for L-Trp and L-Tyr, respectively. Moreover, the electrode displayed a good reproducibility, a long-term stability and a favorable ability of anti-interference to electroactive-molecules.