Colorimetric detection of H2O2 based on the enhanced peroxidase mimetic activity of nanoparticles decorated Ce2(WO4)3 nanosheets

Abstract

In this paper, nanoparticles decorated Ce₂(WO₄)₃ nanosheets (CWNSs) with negative potential and large specific surface area were synthesized and developed as highly efficient peroxidase mimics for colorimetric detection of H₂O₂. CWNSs can efficiently catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H₂O₂ to induce an obvious color variation. Kinetic analysis indicated that the catalytic behaviors of CWNSs obey the typical Michaelis-Menten mechanism. The peroxidase-like catalytic mechanism of CWNSs was proposed according to the active species trapping experiments, verifying that ·O₂^- radicals played primary roles in the catalytic reaction. Based on the strong and stable peroxidase-like catalytic activity of CWNSs, a simple, rapid, selective, and ultrasensitive method was successfully established for colorimetric detection of H₂O₂. The method has a good linear response ranging from 0.5 μM to 100 μM for H₂O₂ concentration with a lower detection limit of 0.15 μM. Benefitting from the sensitive response and good stability, the method is applied in real sample detection and shows a favorable reproducibility and feasibility. This work not only provides a novel enzymatic mimics with remarkable catalytic activities for biomedical and environmental analysis, but also extends the application area of Ce₂(WO₄)₃ materials.

Keywords: Ce(2)(WO(4))(3); Colorimetric detection; H(2)O(2); Nanosheets; Peroxidase mimics.