Microwave excited hyperthermy and catalysis of heterostructured Au/Cu–BTA for effective bacteria killing by accelerating charge separation

Deep tissue infections caused by pathogenic bacteria seriously threat the lives of patients. In this study, a smart heterostructured Au/Cu–BTA (BTA = 1,2,4,5-benzenetetramine) with microwave (MW) response is synthesized via NaBH₄ reduction of HAuCl₄ on the Cu–BTA. Au/Cu–BTA exhibits excellent hyperthermy and dynamics under MW irradiation. The MW thermal mechanism of Au/Cu–BTA is attributed to the excellent dielectric loss and polarization of the heterogeneous interface. Meanwhile, the surface energy levels of the Cu–BTA interface alleviate the difficulty of electron hopping through multistage transition. Therefore, MW can excite Cu–BTA to produce free electrons. Subsequently, Au nanoparticles rapidly increase electron transfer and inhibit electron–hole recombination. Hence, the yields of reactive oxygen species can be enhanced for MW dynamic therapy. Consequently, under 10 min of MW irradiation, Au/Cu–BTA killed 99.998% ± 0.001% of Gram-positive Staphylococcus aureus, 99.966% ± 0.014% of methicillin-resistant Staphylococcus aureus, and 96.871% ± 0.831% of Gram-negative Pseudomonas aeruginosa. The effective MW bacteria-killing strategy designed in this study shows significant potential for application in the MW-responsive treatment of deep tissue infections without antibiotics.