Production of high biocompatibility fluorescent polyamide fabrics using carbon dots derived from natural Malabar spinach seeds

Carbon dots (C-dots) have attracted great attention due to their structurally tunable absorption/emission, biocompatibility, low-cost and facile synthetic methods. Although many types of commercial chemicals have been used as precursors to produce C-dots, it is a challenge to obtain C-dots with good biocompatibility and brightness for textile applications. In this study, we produced colloidal C-dots by using Malabar spinach seeds juice (MSSJ) as a natural precursor, demonstrating the impact of the seeds' chemical composition on C-dots formation and performance. MSSJ contains carbohydrates, protein, glycerol, ethanol, chlorophyll as well as anthocyanin. Based on the variation in composition before and after C-dots synthesis, we determined that the structure of the C-dots is primarily derived from carbohydrates and protein. While chlorophyll remains stable during synthesis at 160 °C. The high nitrogen content from proteins enhances C-dots formation. The C-dots in this work have a high quantum yield of 7.8%, and the emission peak range is 400-525 nm, which is significantly higher than C-dots derived from traditional biomass. Biological tests show no significant biotoxicity at any concentration, ensuring safe use in fluorescent textiles. This study underscores the importance of biomass-derived precursors in green C-dots synthesis, advancing the development of sustainable and biocompatible fluorescent fibers.