Hydrogen-bonded organic framework core–shell composite for synergistic antimicrobial therapy

Hydrogen-bonded organic frameworks (HOFs) are crystalline porous materials with permanent voids formed via self-assembly of organic molecules through hydrogen bonding and intermolecular forces. Further combination of HOFs with functional material would broaden their application horizon but were less explored in existing literature. Herein, a highly porous and photosensitive HOF was successfully coated onto upconversion nanoparticles (UCNPs) to construct a core–shell structure named UNCPs@PFC-73-Ni. To enhance spectral overlap and maximize energy conversion efficiency, this study utilized the Er and Tm co-doped UCNPs, which can effectively convert infrared light into visible light emission thereby exciting the porphyrin shell. Subsequent investigation reveals that the composite exhibits significant photodynamic and photothermal effects under infrared light. Encouraged by its noticeable photoactivity, UCNPs@PFC-73-Ni was evaluated as an antibacterial agent against Escherichia coli. Notably, significant antibacterial efficacy was observed, highlighting the potential of UCNPs@PFC-73-Ni as an effective antibacterial agent under infrared light irradiation.