Ruthenium‐Anchored Ag 2 Se Quantum Dots for Enhanced Near‐Infrared Antibacterial Nanotherapeutics

Light‐activated nanotherapeutics that generate reactive oxygen species (ROS) offer a resistance‐independent antibacterial strategy. However, integrating transition metals with inorganic quantum dots (QDs) to modulate light–matter interactions and extend photoactivity into the near‐infrared (NIR) windows remains largely unexplored for antibacterial applications. Here, we develop a colloidal in situ integration strategy to anchor metallic ruthenium (Ru) onto Ag 2 Se QDs, enabling broadband‐enhanced photoresponse and multimodal generation of superoxide, hydroxyl radicals, and singlet oxygen, alongside a high photothermal conversion efficiency of 66.4%. Moreover, Ru decoration transforms the previously unstable Ag 2 Se QDs into highly robust colloidal suspensions. The Ru‐decorated Ag 2 Se QDs exhibit potent photodynamic and photothermal antibacterial activity against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus under near‐infrared (NIR‐I and NIR‐II) irradiation, extending therapeutic photoactivation beyond the visible range. Ultimately, this work introduces an unconventional biomedical nanoplatform that integrates transition metals with inorganic quantum dots for advanced functionality.