The electrochemical characterization of curcumin and its selective detection in Curcuma using a graphene-modified electrode

A sensitive voltammetric sensor, a graphene-modified glassy carbon electrode (GR/GCE), for the detection of trace amounts of curcumin is proposed. The GR/GCE was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of curcumin at the GR/GCE was investigated by CV and liner sweep voltammetry (LSV). The reaction mechanisms of curcumin on the GR/GCE were also investigated and discussed systematically. In addition, the currents measured by LSV presented a good linear relationship with curcumin concentrations in the range of 5.0 × 10−8 to 3.0 × 10−6 mol L−1, with a low detection limit of 3.0 × 10−8 mol L−1. The method was also applied successfully to detect curcumin in a Curcuma longa L. sample with high selectivity and accuracy, as well as good recovery.