Structure-activity mechanism, multidimensional regulation and cutting-edge cross-disciplinary applications of antioxidant properties of carbon quantum dots.

The excessive accumulation of reactive oxygen species triggered by oxidative stress is a primary driver of various diseases, food spoilage, and material aging. As zero-dimensional carbon-based nanomaterials with sizes below 10 nm, carbon quantum dots (CQDs) have demonstrated immense potential to replace traditional antioxidants, owing to their excellent biocompatibility, tunable optical properties, abundant surface active sites, and low cost. This paper systematically reviews core factors influencing the antioxidant performance of CQDs, including surface functional group characteristics, heteroatom doping effects, size and morphology regulation, electronic structure features, and physicochemical parameters, while providing an in-depth analysis of the regulatory mechanisms and structure-activity relationships. Furthermore, it comprehensively summarizes the research progress of CQDs in antioxidant applications across biomedicine, food preservation, environmental remediation, and anti-aging cosmetics. Finally, the current bottlenecks in CQDs antioxidant research are summarized, and future development directions are prospected, aiming to provide theoretical support and technical references for the precise design, preparation, and practical application of high-performance antioxidant CQDs.