Carbon dot enhanced peroxidase-like activity of platinum nanozymes.

As one of the most intriguing nanozymes, the platinum (Pt) nanozyme has attracted tremendous research interest due to its various catalytic activities but its application is still limited by its poor colloidal stability and low affinity to substrates. Here, we design a highly stable Pt@carbon dot (Pt@CD) hybrid nanozyme with enhanced peroxidase (POD)-like activity (specific activity of 1877 U mg -1 ). The Pt@CDs catalyze the decomposition of hydrogen peroxide (H 2 O 2 ) to produce singlet oxygen and hydroxyl radicals and exhibit high affinity to H 2 O 2 and high specificity to 3,3',5,5'-tetramethyl-benzidine. We reveal that both the hydroxyl and carbonyl groups of CDs could coordinate with Pt 2+ and then regulate the charge state of the Pt nanozyme, facilitating the formation of Pt@CDs and improving the POD-like activity of Pt@CDs. Colorimetric detection assays based on Pt@CDs for H 2 O 2 , dopamine, and glucose with a satisfactory detection performance are achieved. Moreover, the Pt@CDs show a H 2 O 2 -involving antibacterial effect by destroying the cell membrane. Our findings provide new opportunities for designing hybrid nanozymes with desirable stability and catalytic performance by using CDs as nucleating templates and stabilizers.