Cyclodextrin reduced Fe(III) nanozyme-based colorimetric and photothermal dual-mode assay for early monitoring meat freshness by sensitive detection of hypoxanthine

A simple and sensitive method for monitoring the freshness of meat products is crucial for safeguarding food hygiene and human health. Here, we synthesized an environmentally friendly β -CD@Fe nanozyme through a one-pot solvothermal method, enabling colorimetric and photothermal dual-mode detection of hypoxanthine (Hx). In the xanthine oxidase (XOD)/nanozyme enzymatic cascade system, Hx ultimately led to the oxidation of colorless TMB to blue oxTMB, accompanied by enhanced absorbance at 652 nm and an increased temperature under 808 nm laser irradiation. The proposed dual-mode assay for Hx exhibited a good linear relationship in the range of 1–40 μM, achieving low detection limits of 0.29 μM (colorimetric) and 1.0 μM (photothermal), respectively. The β -CD@Fe nanozyme, characterized by its environmental friendliness, mild synthesis conditions, and high peroxidase-like activity, was successfully applied for the sensitive analysis of Hx in actual meat samples. This advancement offers promising potential for applications in food safety supervision.