One-Pot Synthesis of Lanthanum-Doped Carbon Dots From Fumaroyldiglycine With Antioxidant and Antimicrobial Activities

This study presents a novel and simplified method for generating lanthanum-nitrogen-enriched carbon dots (La-NCDs) in a single step, using 2,2'-(fumaroylbis(azanediyl))diacetic acid (FDG) as a starting material. The resulting lanthanum-nitrogen-carbon dots were carefully analyzed for their consistent structure, optical properties, and size, all of which indicated successful activation. The research then explored the antimicrobial potential of both La-NCDs and FDG against common pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans. La-NCDs inhibit microbes greatly, demonstrating inhibition zones of up to 41 mm and minimum inhibitory concentrations (MICs) of 500-2000 µg/mL depending on the microbe. In contrast, FDG displays weak antimicrobial activity. The 1,1-diphenyl-2-picrylhydrazyl/2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay was used to estimate the antioxidant properties of the materials. La-NCDs were more efficient as antioxidants than FDG and inhibited free radicals with an IC₅₀ of 121.88 µg/mL. This indicates that La-NCDs antioxidants may find their place in biomedical applications concerning microbial infection and oxidative stress treatment.