Visible light-activated cobalt phthalocyanine/UiO-67 composite: A novel approach to photodynamic antibacterial therapy

Metallophthalocyanines (MPcs) are highly promising photosensitizers owing to their exceptional photoelectronic properties, yet their practical photocatalytic applications are often limited by strong π–π self-aggregation. In this study, we report a facile in situ strategy to incorporate cobalt phthalocyanine (CoPc) into the porous matrix of UiO-67 metal-organic frameworks (MOFs), effectively suppressing aggregation and enhancing photo-activity. The resulting composite, UCoP2–32, exhibited outstanding antibacterial photodynamic therapy (APDT) performance under visible light, achieving over 96 % inactivation of methicillin-resistant Staphylococcus aureus (MRSA) within 12 min of light exposure. Photophysical studies confirmed the efficient generation of both type-I and type-II reactive oxygen species (ROS), with superoxide and hydroxyl radicals predominating, and electron spin resonance (ESR) analysis supported this mechanism. Moreover, UCoP2–32 demonstrated excellent biocompatibility with minimal hemolysis (∼6.4 % at 110 μM) and structural stability. This work provides a robust and broadly applicable strategy for integrating MPcs into MOFs, offering significant potential for the development of high-performance photocatalytic materials in antimicrobial and other light-driven applications.