A Bimetallic Nanocatalyst For Light-Free Oxygen Sensitization Therapy

Singlet oxygen (O-1(2)) is extensively employed by reactive oxygen species (ROS)-based cancer therapies, such as photodynamic therapy (PDT) and chemodynamic therapy (CDT). However, the dependences of PDT on light and CDT on complex chemodynamic reactions greatly limit their O-1(2)-generating efficiencies. Here, we exploit strain and electronic effects to fabricate a bimetallic nanocatalyst by coating a gold nanorod (AuNR) with similar to 2 platinum(Pt) atomic layers (AuPt0.09), which efficiently generates O-1(2) from ground- state oxygen (O-3(2)) by electron-transfer-mediated spin reduction. Density functional theory reveals strain, and electronic effects promote the adsorption of O-3(2) onto AuPt0.09, which dramatically enhances O-1(2) generation and imparts AuPt0.09, the highest catalytic constant ever reported for 3,3',5,5'-tetramethylbenzidine oxidation to the best of our knowledge. With a pH- dependent catalytic activity, AuPt0.09 realizes acidity-dependent antitumor effects both in vitro and in vivo, a proof-of-concept demonstration of autocatalytic bimetallic nanocatalyst for light-free oxygen sensitization therapy, which may open a new avenue for O-1(2)-centered therapeutics.