Nitrogen-doped biochar as an efficient sensing material for the electrochemical detection of heavy metal ion Pb2+ and Cd2+

The sensitive detection of heavy metal ions with high toxicity and mobility is extremely important for environmental monitoring. In this study, nitrogen-doped biochar (N-BC) was synthesized using waste mushroom bran as a raw material, and nitrogen atoms were successfully doped onto the surface of the biochar via a facile process using an activation-carbonation strategy. The functional groups on the surface of the biochar were enriched via doping, and the roughness of the biochar surface was significantly improved. Experimental results showed that N-BC was an efficient sensing material for electroanalysis; therefore, it was used to construct a novel electrochemical sensing platform. The electrochemical response of the biochar-modified working electrodes was effectively improved for the detection of heavy metals. Under optimized deposition potential, enrichment time, and pH, the N-BC-based sensing platform could detect Pb 2+ and Cd 2+ separately as well as simultaneously, indicating its significant potential for electrochemical sensing.