A simple electrochemical sensor based on rGO/MoS2/CS modified GCE for highly sensitive detection of Pb(ii) in tobacco leaves.

Abstract

High-performance electrode modification materials play a crucial role in improving the sensitivity of sensor detection in electrochemical determination of heavy metals. In this study, a rGO/MoS2/CS nanocomposite modified glassy carbon electrode (GCE) was used to construct a sensitive sensor for detecting lead ions in tobacco leaves. The reduced graphene oxide (rGO) was used to increase the conductivity of the sensor, and the nano-flowered MoS2 could provide a large reaction specific surface area and a certain active site for heavy metal reaction. Chitosan (CS) was used to improve the enrichment ability of heavy metals and increase the electrocatalytic activity of electrode. Thus, an electrochemical sensor with excellent performance in reproducibility, stability and anti-interference ability was established. The stripping behavior of Pb(ii) and the application conditions of the sensor were studied by square wave anodic stripping voltammetry (SWASV). The investigation indicated that the sensor exhibited high detection sensitivity in the range of 0.005–0.05–2.0 μM, and the limit of detection (LOD) was 0.0016 μM. This work can provide a fast and effective method for determination of Pb(ii) in samples with low content, such as tobacco leaves.