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 (H 2 O 2 ) 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 H 2 O 2 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 H 2 O 2 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 H 2 O 2 , generating a blue coloured product. Under the optimal testing conditions, the linear absorbance response is well correlated with the H 2 O 2 concentration ranging from 10 to 100 μM with a detection limit of 0.60 μM. The catalytic kinetic assay suggested that the MIL-88B-Fe MOF possessed the higher affinity towards both the substrate TMB and H 2 O 2 than horseradish peroxidase. Moreover, the MIL-88B-Fe MOF also displayed a high selectivity and anti-interference performance towards H 2 O 2 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 H 2 O 2 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 H 2 O 2 detection in food field.