Membrane-Anchoring Photosensitizer with Aggregation-Induced Emission Characteristics for Combating Multidrug-Resistant Bacteria

Traditional photosensitizers (PSs) show reduced singlet oxygen (¹O₂) production and quenched fluorescence upon aggregation in aqueous media, which greatly affect their efficiency in photodynamic therapy (PDT). Meanwhile, non-targeting PSs generally yield low efficiency in antibacterial performance due to their short lifetimes and small effective working radii. Herein, a water-dispersible membrane anchor (TBD-anchor) PS with aggregation-induced emission is designed and synthesized to generate ¹O₂ on the bacterial membrane. TBD-anchor showed efficient antibacterial performance towards both Gram-negative (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). Over 99.8 % killing efficiency was obtained for methicillin-resistant S. aureus (MRSA) when they were exposed to 0.8 μm of TBD-anchor at a low white light dose (25 mW cm⁻²) for 10 minutes. TBD-anchor thus shows great promise as an effective antimicrobial agent to combat the menace of multidrug-resistant bacteria.