Cu Single-Atom Embedded g-C3N4 nanosheets Rehabilitate Multidrug-Resistant Bacteria Infected Diabetic Wounds via Photoswitchable Cascade Reaction

To tackle elevated blood glucose, multidrug-resistant (MDR) bacterial infections, and persistent inflammation in diabetic wounds, we present a therapeutic strategy that employs a photoswitch-controlled catalytic cascade reaction, utilizing a photocatalytic material engineered through the synergistic regulation of nitrogen vacancies and single-atom embedding. The nitrogen vacancies in g-C3N4 promise the photocatalytic glucose oxidation to H2O2 and facilitate its subsequent conversion into hydroxyl radicals (•OH) through a photocatalytic cascade reaction with Cu single-atom embedded g-C3N4 nanosheets (Cu/CN). Concurrently, the •OH and superoxide anions (•O2⁻) are obtained by photocatalytic water splitting over Cu/CN. Over 99.9% antibacterial activity and effective biofilm inhibition are achieved via photocatalytic cascade reaction. In the dark, excess ROS are scavenged by Cu/CN, reducing inflammation of wounds and promoting polarization of M2 macrophages. This photoswitchable cascade reaction effectively treated MDR bacterial-infected diabetic wounds, highlighting its potential for antibiotic-free diabetic wound therapy and its promising prospects for clinical applications.