Facile preparation of MIL-88B-Fe metal-organic framework with high peroxidase-like activity for colorimetric detection of hydrogen peroxide in milk and beer

Hydrogen peroxide (H2O2) was widely applied as the bactericide and bleach agent in food industry due to its strong oxidation, whose residue had also posed a hazard to public health at the same time. Therefore, it was indispensable to establish a simple, highly effective and accurate method for the detection of H2O2 in foods. Herein, the MIL-88B-Fe metal-organic framework (MOF) was prepared by a facile solvothermal process and utilized as the peroxidase mimic for H2O2 detection. The resultant MIL-88B-Fe MOF exhibited an excellent peroxidase mimetic activity to effectively catalyse the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, generating a blue coloured product. Under the optimal testing conditions, the linear absorbance response is well correlated with the H2O2 concentration ranging from 10 to 100 mu M with a detection limit of 0.60 mu M. The catalytic kinetic assay suggested that the MIL-88B-Fe MOF possessed the higher affinity towards both the substrate TMB and H2O2 than horseradish peroxidase. Moreover, the MIL-88B-Fe MOF also displayed a high selectivity and anti-interference performance towards H2O2 detection. In addition, the peroxidase mimetic catalytic oxidation TMB mechanism over the MIL-88B-Fe MOF was clarified by the photoluminescence test. Benefitting from the sensitive response and good anti-interference capacity, this method was applied in real milk and beer samples for H2O2 detection and showed a favourable reproducibility and feasibility. These results indicated that the proposed method based on MIL-88B-Fe as peroxidase mimic might be a promising candidate for H2O2 detection in food field.

Automated summary

A method for H2O2 detection based on MIL-88B-Fe as peroxidase mimic was established, showing excellent detection performance and high selectivity, making it a promising candidate for H2O2 detection in the food field.