Evaluation of antioxidant, antimicrobial and bacterial labeling capacities of four plant byproduct carbon dots

The comprehensive utilization of food resources has been an issue of interest. In this study, carbon dots (CDs) were prepared by green hydrothermal method using four plant byproducts, and then the preparation of fluorescent CDs was verified by particle size, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis as well as UV and fluorescence spectroscopy. The results showed that all four CDs had particles smaller than 50 nm and at a concentration of 128 μg/mL, CDs had similar ability to scavenge DPPH free radicals as vitamin C. Also, all four CDs had extensive fluorescence properties. In addition, CDs showed good antibacterial properties and fluorescence properties against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. These findings suggest that these four CDs have a promising future in the field of food detection and preservation, and provide useful information for the thorough utilization of food resources.