Electroanalytical approach for determination of tanshinone IIA based on electrochemically reduced graphene oxide modified gold nanoparticles-incorporated carbon paste electrode

In this work, a novel electrochemical sensor was presented for Tanshinone IIA determination. The as-prepared electrode was prepared by electrodepositing a reduced graphene oxide film onto a carbon paste electrode modified with gold nanoparticles, which combined the advantages of both gold nanoparticles and electrochemically reduced graphene oxide. It was characterized with scanning electron microscopy and cyclic voltammetry. The electrochemical behavior of Tanshinone IIA at the modified electrode was investigated for the first time. Results revealed that the modified electrode can effectively increase response toward Tanshinone IIA by significantly enhancing the redox peak currents and decreasing the peak-to-peak separation. Under the optimized conditions, the modified electrode showed a linear voltammetric response to Tanshinone IIA at concentrations ranging from 5.0×10-8mol L-1 to 1.0×10-5mol L-1, with a detection limit of 1.0×10-8mol L-1 (S/N=3). The proposed method was successfully applied in determination of Tanshinone IIA in pharmaceutical samples with satisfactory results.