Novel Reducibility-Tunable Carbon Dots for Efficient Radicals Scavenging and Material-Controlled Synthesis

The development of efficient, nontoxic, and low-cost nano-antioxidants has attracted extensive attention in food preservation but still remains a great challenge in materials design and mechanism exploration. Herein, novel reductive carbon dots (r-CDs) were successfully synthesized via a simple pyrolysis technique using sucrose as the precursor. The experimental results show that r-CDs possess excellent reducibility, and can effectively scavenge a variety of reactive oxygen and nitrogen species (RONS). So, the r-CDs exhibit remarkable preservation effects on apples and strawberries and significantly extend their shelf-life. Mechanistic studies reveal that their outstanding reducibility/antioxidant property is attributed to the formed carbon-core and numerous hydroxyl groups in the pyrolysis process. More interestingly, the reducibility of r-CDs can be gradually regulated by nitrogen doping, the obtained N-doped CDs (N-CDs) can be used to synthesize gold nanomaterial with different morphology and size, proving its potential applications in material-controlled synthesis. This study provides a new idea for the development of non-toxic, efficient carbon nano-antioxidants with tunable reducibility for food preservation and material-controlled synthesis.