Alternanthera sessilis derived fluorescent carbon dots and their sensing and biological applications

Abstract

Herein, the green synthesis of novel fluorescent carbon dots (CDs) from the Alternanthera sessilis plant by a simple, eco-friendly, and facile hydrothermal method was reported. The developed CDs exhibit green fluorescence and have a size of 5.25 nm. Various analyses reveal outstanding features, including high quantum yield, good photostability, and excellent hydrophilicity of the as-synthesized CDs. It was used as a dual-mode probe for the sensing of Cu2+ ions and Zn2+ ions in an aqueous system. Efficient sensing of Cu2+ ions takes place by static quenching of fluorescence with a detection limit of 28.03 nM. CDs-coated glassy carbon electrode was used to perform the electrochemical detection of Zn2+ ions in an aqueous system with high selectivity and sensitivity, and the LOD value was found to be 2.28 nM. The LC50 value of the fabricated CDs against the human breast cancer cell line is 89.85 µL/mL. Also, the antimicrobial efficacy of the CDs was examined against Escherichia coli, Staphylococcus Aureus, and Aspergillus niger, and the results indicate the high toxicity of the CDs against all tested microbial strains.