Copper/gold-modified porphyrinic metal–organic frameworks nanoprobes for enhanced photodynamic/chemodynamic therapy

Porphyrinic metal–organic frameworks (MOFs) had promising applications in the photodynamic therapy (PDT) and chemodynamic therapy (CDT) of cancers, but the insufficient reactive oxygen species restricted the efficacy. Herein, by coordinating Cu2+ and coating ultrasmall gold nanoparticles (AuNPs), a bi-functional porphyrinic MOFs (PCN-224) nanoplatform (PCN-224(Cu)-Au) was designed, achieving the dual-enhancement of PDT/CDT. The results indicated that the Cu2+ was doped in the core of porphyrin ring, and the singlet oxygen (1O2) generation increased from 79.9% to 85.7%, owing to the enhanced capture capability of photogenerated electrons by Cu2+. Using the glucose oxidase-like property of ultrasmall AuNPs, the produced hydrogen peroxide (H2O2) promoted the Fenton-like reaction of Cu+, by which the hydroxyl radicals (OH) generation increased from 63.2% to 80.3%, exhibiting the enhanced CDT performance. Under the combination of enhanced PDT/CDT, the cell viability reduced to 9.1%, and the tumors disappeared completely, demonstrating the dual-enhancement effect of PCN-224(Cu)-Au nanoprobe.