Single-atom engineering enhanced photodynamic sterilization of 2D In-TCPP MOF nanosheets

Atomic layer deposition (ALD) is utilized to precisely construct Pt single atoms and Pt nanoparticles on In-TCPP nanosheets. • The Pt single-atom sites are shown to markedly enhance photodynamic performance by facilitating charge separation and increasing singlet oxygen ( 1 O 2 ) generation compared to Pt nanoparticles. • The resulting Pt SA /In-TCPP composite achieves broad-spectrum photodynamic inactivation against both S. aureus and E. coli via a 1 O 2 -dominated oxidative stress pathway. In the face of the increasingly serious threat of multidrug-resistant bacteria, it is urgent to develop new non-antibiotic antibacterial strategies. Photodynamic therapy (PDT) has attracted much attention due to its advantages of low invasiveness, controllable time and space, and not easy to induce drug resistance, but its efficacy is highly dependent on the photogenerated charge separation efficiency of photosensitizers. In this study, Pt single atoms (Pt SAs) and platinum nanoparticles (Pt NPs) were precisely constructed on the surface of two-dimensional porphyrin metal organic framework (In-TCPP) nanosheets by atomic layer deposition technology. The size effect of platinum species and the enhancement mechanism of single atom construction on photodynamic performance were systematically explored. The evaluation of photodynamic performance shows that Pt single atom modified In-TCPP (Pt SA /In-TCPP) is superior to Pt nanoparticles modified In-TCPP and In-TCPP in the efficiency of generating total reactive oxygen species and singlet oxygen. In vitro antibacterial experiments showed that Pt SA /In-TCPP exhibited excellent broad-spectrum bactericidal performance under 660 nm laser irradiation. This study confirms that the controllable construction of single atom sites by ALD technology is an effective strategy to improve the photodynamic sterilization efficiency of MOF, and provides a new idea for the development of high-performance antibacterial nanomaterials. Multidrug-resistant bacteria pose a severe threat, necessitating antibiotic-free strategies. Herein, Pt single atoms are precisely deposited on 2D In-TCPP MOF nanosheets via atomic layer deposition. Notably, Pt SA /In-TCPP exhibits excellent broad-spectrum photodynamic sterilization against both S. aureus and E. coli under 660 nm laser irradiation, achieving complete bacterial inactivation. Download: Download high-res image (154KB) Download: Download full-size image