NIR‐Activated Ag ₂ S Quantum Dots for Efficient Broad‐Spectrum Antibacterial and Biofilm Disruption

ABSTRACT Bacterial biofilms, encased in a protective extracellular polymeric substance (EPS) matrix and harboring metabolically dormant persister cells, pose a critical challenge in antimicrobial therapy due to their inherent resistance to conventional antibiotics. To overcome this, we present a near‐infrared (NIR)‐activated nanoplatform based on silver sulfide quantum dots (Ag ₂ S QDs) that synergistically integrates photothermal therapy (PTT) and photodynamic therapy (PDT). Under NIR irradiation, Ag ₂ S QDs rapidly generate localized hyperthermia and reactive oxygen species (ROS). This leads to complete eradication (99.99%) of planktonic bacteria within 10 min, as well as significant disruption of pre‐established biofilms (69–84% removal). The mechanism involves photothermal‐mediated degradation of the EPS barrier to facilitate deep penetration, and ROS‐induced oxidative damage to bacterial membranes and intracellular components. This strategy exhibits a physical barrier‐disruption paradigm that circumvents conventional antibiotic resistance mechanisms, demonstrating broad‐spectrum activity, a well‐defined therapeutic index, and spatiotemporally controllable biosafety for the precision treatment of biofilm‐associated infections.