Two-Dimensional Conjugated Metal Organic Frameworks with Dual Metal Catalytic Active Sites Enhance POD Activity for Antibacterial Treatment.

The emergence of drug-resistant bacteria has brought a grand challenge to the treatment of oral ulcers (OUs). Peroxidase (POD) enzymes catalyze the conversion of hydrogen peroxide (H2O2) into reactive oxygen species (ROS), offering a promising strategy for treating drug-resistant bacterial infections and oral wound therapy. Among them, two-dimensional conjugated metal-organic frameworks (2D-cMOFs) with high π-π conjugated structure and efficient electron transport capability serve as potent POD mimics, enhancing ROS generation for targeted antimicrobial applications. However, the reported single-metal-center 2D cMOFs possess the intrinsically weak adsorption interaction with H2O2, usually decreasing the conversion of H2O2 to ROS, exhibiting relatively low enzymatic activity and antibacterial performance. Herein, we reported a new class of Ni doped Cu 2D cMOFs, defined as CuNi-HHTP 2D-cMOFs, for constructing dual activity site to enhance the adsorption and activation of H2O2, which significantly facilitates the treatment of OUs. Mechanism investigation reveals the introduction of Ni atom upshifts the d-band center of CuNi-HHTP 2D-cMOFs from -2.563 to -2.084 eV, which enhances the adsorption and activation of H2O2, endowing its 5.0-fold enhancement in bactericidal efficiency. Besides, the as-made CuNi-HHTP 2D-cMOFs show improved antibacterial performance in vivo, which significantly promote OU healing, with macroscopic wound closure on the 7th day.