Nanozyme-Based Sensors: Advancing Antioxidant Analysis and Total Antioxidant Capacity Evaluation in Foods

Food total antioxidant capacity (TAC) reflects the free‑radical‑scavenging ability of its antioxidant components, thereby indicating oxidation resistance and serving as a key quality and stability indicator. Quantification of typical antioxidants (AOs) such as ascorbic acid (AA), glutathione (GSH), cysteine (Cys), and polyphenolic compounds (polyphenols) is the main approach to assess TAC. Nanozymes are nanomaterials with enzyme-mimetic activities, combining the physicochemical properties of nanomaterials and high catalytic efficiency of natural enzymes. They have been widely used in food detection, mainly including metal, metal oxide, carbon-based, and metal-organic frameworks (MOFs)-derived nanozymes. Nanozyme sensors, with high sensitivity, simple operation, visual signal output, and low cost, have significantly promoted the detection of food TAC. This review systematically summarizes recent progress in the detection of representative AOs and the evaluation of food TAC using nanozymes. It provides an in-depth analysis of the advantages and potential applications of nanozymes in identifying and quantifying food TAC through mechanisms such as colorimetry, fluorescence, electrochemistry, chemiluminescence (CL), and Raman spectroscopy. Furthermore, the review objectively examines the current challenges facing nanozyme-based technologies for detecting food AOs and evaluating TAC, including issues related to the stability of catalytic performance, cost, and the lack of standardized detection protocols. Building on existing research, it also outlines future development pathways and broad prospects for these technologies. By offering a comprehensive perspective on the application status of nanozymes in detecting AOs for TAC evaluation, this review aims to provide insights and inspiration for their future application and development.