Multiple application of SAzyme based on carbon nitride nanorod-supported Pt single-atom for H2O2 detection, antibiotic detection and antibacterial therapy

Abstract Nanozymes currently face challenges in respect to their structure, properties, and mechanism compared to natural enzymes. Single-atom nanozymes (SAzymes) can realize the maximum metal atom utilization and the possibility of overcoming inherent limitations. Herein, a SAzyme based on Pt single atoms modified carbon nitride nanorod (SA-Pt/g-C3N4-K) was synthesized, and exhibits peroxidase-mimicking activity for antibiotic detection and antibacterial applications. Both experimental results and density functional theory calculations reveal that the Pt-N-C structure of SA-Pt/g-C3N4-K significantly enhances OH generation via reducing the desorption energy of the intermediate state of OH* from the active site during H2O2 activation. Notably, the peroxidase-like activity of SA-Pt/g-C3N4-K can be regulated by the aptamer, and guarantees the SAzyme with high sensitivity to antibiotic. Moreover, SA-Pt/g-C3N4-K nanozyme shows remarkable hydroxyl radical-mediated in vitro gram-negative bacteria inactivation performance with killing efficiency > 99.99 % in the presence of 1 mM H2O2 and enabled healing of gram-negative bacteria-infected wounds. This work provides new insights into designing highly efficient multifunctional SAzymes for environmental and biological applications.