Red‐Light‐Mediated Photoredox Catalysis Enables Self‐Reporting Nitric Oxide Release for Efficient Antibacterial Treatment

Abstract Nitric oxide (NO) serves as a key regulator of many physiological processes and as a potent therapeutic agent. The local delivery of NO is important to achieve target therapeutic outcomes due to the toxicity of NO at high concentrations. Although light stimulus represents a non‐invasive tool with spatiotemporal precision to mediate NO release, many photoresponsive NO‐releasing molecules can only respond to ultraviolet (UV) or near‐UV visible light with low penetration and high phototoxicity. We report that coumarin‐based NO donors with maximal absorbances at 328 nm can be activated under (deep) red‐light (630 or 700 nm) irradiation in the presence of palladium(II) tetraphenyltetrabenzoporphyrin, enabling stoichiometric and self‐reporting NO release with a photolysis quantum yield of 8 % via photoredox catalysis. This NO‐releasing platform with ciprofloxacin loading can eradicate Pseudomonas aeruginosa biofilm in vitro and treat cutaneous abscesses in vivo.