Interface-Engineered CuO@BiMoO Heterojunctions to Inhibit Piezoelectric Screening Effect and Promote Double-Nanozyme Catalysis for Antibacterial Treatment.

Sonodynamic therapy is confronted with the low acoustic efficiency of sonosensitizers, and nanozymes are accompanied by intrinsic low catalytic activity. Herein, to increase the piezopotential of N-type piezoelectric semiconductors, the P-N heterojunction is designed to inhibit the piezoelectric screening effect (PSE) and increase electron utilization efficiency to enhance nanozyme activity. P-type CuO nanoparticles are in situ grown on N-type piezoelectric BiMoO (BMO) nanoflakes (NFs) to construct heterostructured CuO@BMO by interface engineering. CuO deposition leads to lattice distortion of BMO NFs to improve piezoelectric response, and the strong interface electric field (IEF) suppresses PSE and increases piezopotential. The nonlocal piezopotential, local IEF, and glutathione (GSH) inoculation enhances electron-hole separation and increases peroxidase (POD)-like activity of BMO and GSH oxidase (GSHOx)-like activity of CuO with high selectivity. The heterojunction formation causes the transfer and rearrangement of interface electrons, and the increased piezopotential accelerates electron transfer at interfaces with bacteria, thus increasing the production of reactive oxidative species and interfering with adenosine triphosphate synthesis. The heterostructured nanozymes produce abundant intracellular ·OH and achieve 4log magnitude reductions in viable bacteria and effective biofilm dispersion. This study elucidates integral mechanisms of nanozyme and acoustic catalysis and opens up a new way to synergize high piezopotential and nanozyme-catalyzed therapy.