Abstract
In this study, we used biomass banana peel (BP) as the precursor to synthesize CDs (defined as BP-CDs). The average sizes of BP-CDs were found to be around 5.9 nm. The prepared BP-CDs presented blue fluorescence under ultraviolet irradiation at 365 nm and exhibited excitation-wavelength-dependent fluorescence properties. Furthermore, the nitrogen-containing, oxygen-containing and sulfur-containing functionalities on/in the surface of carbon structure were observed in the resulting CDs. The antioxidant assays in vitro suggested that BP-CDs displayed strong free-radical scavenging abilities. The results of antimicrobial experiments revealed that BP-CDs exhibited noteworthy antimicrobial effects against spoilage bacteria of aquatic products. Metabolomics analysis revealed that BP-CDs exerted antibacterial activity mainly by impeding normal cell metabolism, disrupting cell wall integrity, affecting substance transport and signal transduction. Taken together, these data suggest that BP-CDs could be used as an antioxidant and antibacterial agent for the development of new preservation technologies for aquatic products.