Unraveling the Structure Transition and Peroxidase Mimic Activity of Copper Sites Over Atomically Dispersed Copper-Doped Carbonized Polymer Dots.

The lack of systematic structural resolution makes it difficult to build specific transition metal atoms-doped carbonized polymer dots (TMAs-doped-CPDs). Herein, the structure-activity relationship between Cu atoms and CPDs was evaluated by studying the peroxidase-like properties of Glu-Cu-CPDs prepared by using copper glutamate (Glu) with Cu-N2O2 initial structure. The results showed that the Cu atoms bound to Glu-Cu-CPDs in the form of Cu-N2C2, indicating that Cu-O bonds changed into Cu-C bonds under hydrothermal conditions. This phenomenon was also observed in other Cu-doped-CPDs. Moreover, the carboxyl and amino groups content decreased after Cu-atom doping. Theoretical calculations revealed a dual-site catalytic mechanism for catalyzing H2O2. Eventually, the detection of intracellular H2O2 suggested their application prospects. Our work provides an in-depth understanding on the formation and catalysis mechanism of TMAs-doped-CPDs, allowing for building specific TMAs-doped-CPDs.