A Cu-based metal–organic framework with high specificity and efficient peroxidase-like catalytic activity for colorimetric biosensing

Abstract

Despite extensive studies demonstrating that nanozymes show superior properties compared to natural enzymes and traditional artificial enzymes, the development of highly specific nanozymes is still a challenge. In this study, a novel metal–organic framework (MOF), [Cu(TCPP)-(DMF)] (ZJU-132), was synthesized under mild mixed solvothermal conditions. It is constructed using 2,3,5,6-tetrakis (4-carboxyphenyl)pyrazine (H₄TCPP) and Cu clusters. ZJU-132 is capable of bifunctional enzyme-mimicking activity with oxidase- and peroxidase-like activities. The catalytic activities were examined by using o-phenylenediamine (OPD) as a chromogenic substrate to study oxidase- and peroxidase-like mimics. In this study, we first propose that ZJU-132, containing dinuclear copper centers mimicking the active sites of natural peroxidase, shows efficient peroxidase activity with good specificity and obvious superoxide dismutase-like or catalase-like activities. Meanwhile, ZJU-132 has good specificity and high catalytic efficiency as a novel OPD peroxidase nanozyme with linear ranges (25–250 µM and 500–1000 µM) and a low detection limit (17 µM). The successful construction of ZJU-132 provides a rational blueprint for the targeted design of highly specific nanozymes, opening new avenues for the practical translation of nanozymes in complex biological and environmental detection scenarios.