A Simple, but Highly Sensitive, Graphene-based Voltammetric Sensor for Salvianic Acid A Sodium

A simple, but highly sensitive, electrochemical sensor for the determination of salvianic acid A sodium (SAS) based on reduced graphene oxide (rGO) is reported. The sensor (rGO/GCE(ox)) was prepared by coating an rGO film on the surface of a pre–anodized glassy carbon electrode (GCE(ox)) through a dipping-drying method. The characteristic of the modified electrode was examined by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Compared with bare GCE, GCE(ox) and rGO modified GCE, this sensor exhibited a superior ability for detecting SAS. Under the selected conditions, the reduction current had a good linear relationship with the SAS concentration in the range of 8.0 × 10–8 - 2.0 × 10–5 mol L–1, with a low detection limit of 2.0 × 10–8 mol L–1. Furthermore, the method was also successfully applied to detect SAS in medicinal tablets.