Carbon dots as new antioxidants: Synthesis, activity, mechanism and application in the food industry

Antioxidants not only prevent food spoilage, but also maintain the nutritional value of food, thereby exerting a crucial protective effect on food industry. Nanomaterials have recently been used as antioxidants because of their remarkable potential to scavenge free radicals. Of them, owing to their relatively high biocompatibility and unique physicochemical properties, carbon dots (CDs) have garnered considerable attention. This paper reviews research progress on CDs as new antioxidants. We here first discuss the methods for synthesizing various antioxidant CDs, followed by the antioxidant activities of different CDs and factors influencing these activities. Then, the possible action mechanisms of antioxidant CDs are discussed. The review particularly focuses on the application of antioxidant CDs, especially in the food industry, including antioxidant coatings, antioxidant packaging materials, and nano-level food additives. Finally, the challenges and prospects for CDs as new antioxidant are described.