Development of an electrochemically reduced graphene oxide modified disposable bismuth film electrode and its application for stripping analysis of heavy metals in milk

• An electrochemically reduced graphene oxide film modified disposable electrode was present.
• Excellent stripping performance for cadmium and lead was obtained.
• Satisfactory results were achieved in the quantitative analysis of milk sample extracts.

A novel electrochemical sensing platform based on electrochemically reduced graphene oxide film modified screen-printed electrode was developed. This disposable electrode shows excellent conductivity and fast electron transfer kinetics. By in situ plating bismuth film, the developed electrode exhibited well-defined and separate stripping peaks for cadmium and lead. Several parameters, including electrolytes environment and electrodeposition conditions, were carefully optimized to achieve best stripping performance. The linear range for both metal ions at the disposable bismuth film electrode was from 1.0 μg L−1 to 60.0 μg L−1. The detection limit was 0.5 μg L−1 for cadmium ion and 0.8 μg L−1 for lead ion. Milk sample analysis demonstrates that the developed electrode could be effectively used to detect low levels (μg L−1) of cadmium ion and lead ion. Graphene based disposable bismuth film electrode is a sensitive, stable, and reliable sensing platform for heavy metals determination.