Voltammetric Behavior of Semicarbazide at Graphene Modified Electrode and Application to Detection.

Herein voltammetric behaviors of semicarbazide (SEM) are investigated by employing a graphene modified working electrode, which displays attractive electroanalytical properties. In the acetate buffer solution of pH 4.00, there is a well-defined oxidative peak of SEM, attributing to the irreversible and adsorption-controlled electrode reaction with 2 electrons participation. The values of apparent heterogeneous electron transfer rate constant k′s with the redox are 0.0061 s−1 and 0.0009 s−1, respectively, for two scan rate section. After the experimental parameters, which influence the voltammetric responses of SEM, including supporting electrolyte, pH, accumulation time and accumulation potential, etc., are optimized, it is found that the anodic peak current of SEM is proportional to its concentration in the range of 4 - 40 μmol/L with a detection limit of 1 μmol/L (S/N = 3). Then, an electrochemical method for detecting SEM quantitatively is developed successfully. The concentrations of SEM in fortified tap water samples are tested with satisfactory recovery, indicating that the novel method is strongly promising in the environmental monitoring application. [ABSTRACT FROM AUTHOR]