Zirconium-porphyrin-MOF-based oxidase-like nanozyme with oxygen vacancy for aflatoxin B1 colorimetric sensing.

In this study, a porous coordination network zirconium-porphyrin-based nanoparticle with oxygen vacancies (OVs) was prepared using acetic acid and benzoic acid as modulators via a simple hydrothermal method. The presence of OVs was confirmed by various characterization methods and was found to enhance oxygen uptake and activation. This resulted in the generation of more reactive peroxyl radicals (•O 2 - ) and led to an improved oxidase (OXD) mimetic activity. Additionally, it promoted 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) oxidation, with a low K m value of 0.07 mM and a high V max of 1.47 × 10 -7  M·s -1 . As aflatoxin B1 (AFB1) inhibits the Pt@PCN-222-ABTS nanozyme system, a colorimetric probe for AFB1 detection was constructed. The limit of detection (LOD) was 0.074 µg·L -1 . This research presents a novel approach for designing a nanozymatic-based colorimetric method to analyze trace AFB1 residues in food.