Near-Infrared Emissive Cascaded Artificial Light-Harvesting System with Enhanced Antibacterial Efficiency

Combination of platinum(II) metallacycles and photodynamic inactivation presents a promising antibacterial strategy. Herein, a cascaded artificial light-capturing system is developed in which an aggregation-induced emission-active platinum(II) metallacycle (PtTPEM) is utilized as the antenna, sulforhodamine 101 (SR101) as a key conveyor, and the near-infrared emissive photosensitizer Chlorin-e6 (Ce6) as the final energy acceptor. The well-dispersed Ce6 in the proximity of energy donors not only avoids self-quenching in the physiological environment but also contributes to energy transfer from donor to acceptor, thereby significantly improving the O-1(2) generation ability of the light-harvesting system under white light irradiation. By integrating the platinum(II) metallacycle and O-1(2), a more efficient synergistic antibacterial effect is achieved at low concentrations, along with a significant decrease in dark toxicity caused by PtTPEM.