Voltammetric Determination of Sophoridine Based on Gold Nanoparticles/L‐cysteine/ Graphene Modified Glassy Carbon Electrode

A new strategy to make the electrochemical sensor was presented, through combining gold nanoparticles (GNPs) with reduced graphene oxide (rGO) via L-cysteine (L-cys) as crosslinker. The resulting electrodes were characterized by scanning electron microscopy (SEM) and electrochemical methods. And it was applied to develop a high-sensitive electrochemical sensor for determination of sophoridine. Compared with the bare GCE and reduced graphene oxide modified electrode, the resulting electrodes exhibited excellent response toward the oxidation of sophoridine by significantly enhancing the oxidation peak currents and decreasing the overpotential of sophoridine. Under the selected conditions, there exist the linear relation between the oxidation peak currents and sophoridine concentration in the range of 1.0 x 10(-6)approximate to 1.0 x 10(-4) mol L-1, with detection limit of 4.0 x 10(-7) mol L-1. At the same time, the method can be successfully applied to the quantitative determination of sophoridine in injection samples and its result is satisfactory.