Cu²⁺‐Modified Metal–Organic Framework Nanoparticles: A Peroxidase‐Mimicking Nanoenzyme

The synthesis and characterization of UiO‐type metal–organic framework nanoparticles (NMOFs) composed of Zr 4+ ions bridged by 2,2′‐bipyridine‐5,5′‐dicarboxylic acid ligands and the postmodification of the NMOFs with Cu 2+ ions are described. The resulting Cu 2+ ‐modified NMOFs, Cu 2+ ‐NMOFs, exhibit peroxidase‐like catalytic activities reflected by the catalyzed oxidation of Amplex‐Red to the fluorescent Resorufin by H 2 O 2 , the catalyzed oxidation of dopamine to aminochrome by H 2 O 2 , and the catalyzed generation of chemiluminescence in the presence of luminol/H 2 O 2 . Also, the Cu 2+ ‐NMOFs mimic NADH peroxidase functions and catalyze the oxidation of dihydronicotinamide adenine dinucleotide, NADH, to nicotinamide adenine dinucleotide, NAD + , in the presence of H 2 O 2 . The Cu 2+ ‐NMOFs‐catalyzed generation of chemiluminescence in the presence of luminol/H 2 O 2 is used to develop a glucose sensor by monitoring the H 2 O 2 formed by the aerobic oxidation of glucose to gluconic acid in the presence of glucose oxidase. Furthermore, loading the Cu 2+ ‐NMOFs with fluorescein and activating the catalyzed generation of chemiluminescence in the presence of luminol/H 2 O 2 yield an efficient chemiluminescence resonance energy transfer (CRET) process to the fluorescein reflected by the activation of the fluorescence of the dye (λ = 520 nm, CRET efficiency 35%).