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

In this paper, nanoparticles decorated Ce 2 (WO 4) 3 nanosheets (CWNSs) with negative potential and large specific surface area were synthesized and developed as highly efficient peroxidase mimics for colorimetric detection of H 2 O 2. CWNSs can efficiently catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H 2 O 2 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 ·O 2 – 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 H 2 O 2. The method has a good linear response ranging from 0.5 μM to 100 μM for H 2 O 2 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 Ce 2 (WO 4) 3 materials. Unlabelled Image • Ce 2 (WO 4) 3 nanosheets were developed as highly efficient peroxidase mimics for colorimetric detection of H 2 O 2 firstly. • CWNSs possessed a nice peroxidase-like activity owing to the negative potential and large specific surface area. • CWNSs exhibited a stronger binding affinity with TMB compared to HRP. • A rapid and ultrasensitive method was established for detecting H 2 O 2 based on CWNSs with a detection limit of 0.15 μM. • The sensing system revealed a high selectivity, stability and reusability. [ABSTRACT FROM AUTHOR]