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

Abstract

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 1O2 generation ability of the light‐harvesting system under white light irradiation. By integrating the platinum(II) metallacycle and 1O2, a more efficient synergistic antibacterial effect is achieved at low concentrations, along with a significant decrease in dark toxicity caused by PtTPEM.

Recent advances in combatting bacterial infections via well-designed metallacycles/metallacages

“…They used SCCs6-SR101-Ce6 -based LHS for photodynamic inactivation. 51 As shown in Fig. 4E and F, under white light irradiation, the survival rate of S. aureus treated with SCCs6-SR101-Ce6 (3 μM) was almost 0%, of which the survival rate was significantly reduced compared to that treated with only SCCs6-SR101-Ce6 or Ce6 .…”

“…1C) acts as an energy donor, SR101 acts as the relay acceptor, and Ce6 acts as the final energy acceptor. 51 This TPE-LHS was obtained through the self-assembly of SCCs6 , followed by a load of negatively charged SR101 through electrostatic interactions and Ce6 . These LHS achieved higher energy transfer efficiency and efficiently generated singlet oxygen ( 1 O 2 ) under light irradiation through a two-step energy transfer process.…”