Visual self-powered platform for ultrasensitive heavy metal detection designed on graphdiyne/graphene heterojunction and DNAzyme-triggered DNA circuit strategy

Self-powered electrochemical biosensors based on enzyme biofuel cells (EBFC) are uniquely valuable in developing real-time and on-site detection of heavy metal ions. This work combines graphdiyne/graphene (GDY/GR) heterojunction with Deoxyribozyme (DNAzyme) trigger catalytic hairpin self-assembly (CHA) circuit. In addition, the smartphone is introduced to obtain the detection signals. The results show that the designed sensor platform can be used for single-tube ultrasensitive and visual lead ion detection with a wide linear range of 0.003–5000 nM and a low detection limit (LOD) of 0.005 nM. This design enriches the routine screening methods for heavy metal ions in food and environmental samples and introduces new idea for the development and application of self-powered electrochemical biosensors.