Covalently bridge metals to biomass carbon for sensing DA and FA with high specificity and sensitivity

Due to the high catalytic activity and electrical conductivity, "transition metal-nonmetal" compounds have broad application prospects in the construction of electrochemical sensors. However, it is still a challenge to solve the problem of catalyst deactivation and slow electron transfer due to nanoparticle agglomeration's blockage of active sites. Here, we prepare a series of covalently bonded "C-M-O" bridge bonds on biomass carbon for the first time. The bridge bonds have a straight-like "electron path", which shortens the electron transfer path and im-proves the electrical conductivity, and catalytic activity. The bridge bonds exhibit excellent catalytic activity even after being subjected to prolonged mechanical external forces. Besides, the bridge bonds can integrate a biosensor with MIP and exhibit excellent electrocatalytic performance, including high sensitivity, low detection limit, excellent stability, superior interference immunity, and the ability to accurately monitor DA and FA released from real samples and live cells in real time. The strategy of forming "C-M-O" bridge bonds based on covalently bonded supports provides a new perspective for solving the agglomeration of nanocatalysts blocking active site deactivation and improving electron transfer rate.