Trimetallic Fe3O4@Au/MOF nanopolyhedrons with peroxidase-like catalytic activity for the electrochemical detection of tert-butyl hydroquinone as a pollutant in edible oil

Abstract

To ensure edible oil quality and safety, herein, superior hybrid magnetic nanocomposites with an enhanced peroxidase-like activity were demonstrated, which exhibited electrochemical detection of TBHQ in edible oil. Gold nanoparticles (AuNPs) and magnetic Fe₃O₄ NPs were embedded in an organic framework by a simple self-assembly method to fabricate Fe₃O₄@Au/MOF nanocomposites validated through various characterization techniques. The effective combination of Fe₃O₄ NPs, AuNPs and Cu-MOF exhibited high electrocatalytic activity of Fe₃O₄@Au/MOF, promoting charge transfer and more sensing sites. Due to its enhanced peroxidase-like activity, Fe₃O₄@Au/MOF catalyzes H₂O₂ to generate oxidatively active radicals. On the basis of these results, the redox reaction of TBHQ can be further promoted and the accurate quantitative detection of TBHQ can be achieved. Results displayed that Fe₃O₄@Au/MOF employed for electrochemical sensing of TBHQ exhibited a low detection limit of 0.3323 μM (S/N = 3) in the concentration range of 1–100 M. Moreover, the results of the electrochemical assays proposed to measure TBHQ in five common edible oils show a good correlation with the actual amount added. The nanocomposite demonstrated good stability, repeatability, reproducibility and sensitivity in real samples, which ensures its practical applicability in edible oil antioxidant analysis as an electrochemical sensor.