Electrochemical Sensing of Dopamine at Biogenic Gold Nanoparticles Interface

A simple biogenic synthetic route for the development of gold nanoparticles (Au NPs) from the fresh pods of Lablab purpureus was carried out. Further, Au NPs modified electrode employed for the selective sensing of dopamine. The stability, surface morphologies, microstructure and elemental compositions of the nanoparticles were probed by dynamic light scattering (DLS) with zeta potential, transmission electron microscopy (TEM), energy dispersive X-ray diffraction (EDX) and X-ray diffraction (XRD). The electrochemical features of dopamine at Au NPs modified glassy carbon electrodes (GCEs) was investigated in 0.1 M phosphate buffer solution (pH 7.4) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Gold nanoparticles modified GCEs in comparison with bare electrodes shows the significant catalytic activity towards dopamine from CV and DPV with limit of detection 5.9 nM and 7.7 nM, respectively. Additionally, the peak current response of dopamine does not interfered with the coexistence of ascorbic acid, uric acid and glucose.