Three-photon absorption platinum (II) complexes based on DNA and L-lysine recognition for photodynamic antimicrobial therapy

New agents for treating bacterial infections and promoting wound healing are urgently needed in facing the crisis of multidrug-resistant bacteria. The multi-photon AIE complex has good tissue penetration, low energy loss and high resolution, hence, multi-photon AIE complexes have great potential in the treatment of bacterial infections. In this work, platinum (II) complex FLPt1 exhibits better three-photon AIE performance (1450 nm) than FLPt2 in DMSO/H2O system. There are variety of intermolecular forces in FLPt1 and FLPt2 through terminal substituent regulation, leading to the difference in three-photon AIE performance. Furthermore, FLPt1/FLPt2 can induce mitochondrial collapse, and effectively responds to L-lysine and DNA by electrostatic bonding. FLPt1/FLPt2 aggregates around bacteria and destroys bacterial walls containing L-lysine. FLPt1/FLPt2 enters the bacteria and damages the DNA, leading to the bacteria death. From the above all, this work enriches existing antibacterial arsenals and facilitates the development of more promising antibacterial agents with platinum complexes in the future.