In vitro antimicrobial and anticancer potentials of green synthesized luminescent carbon quantum dots derived from artichoke leaves

Naturally derived carbon quantum dots (CQDs) are novel carbon-based nanomaterials with excellent traits. It is highly demanded to develop CQDs from biowaste that have excellent photostability, a simple synthesis approach, and an appealing output so that they can be used widely in various fields. Herein, highly fluorescent CQDs were synthesized hydrothermally using artichoke leaves. The CQDs were synthesized and analyzed for their structure, optical properties, antimicrobial, and anticancer activities. The CQDs exhibited antimicrobial action against a single fungus strain in addition to Gram-positive and Gram-negative cells; also, the cytotoxicity against the MCF-7 cell line was evaluated as 96.5 µg/mL. The findings indicated that the spherical dots have a semi-spherical shape with the smallest size of 2.88 nm, and a zeta potential value of 37.31 V, thus confirming that the synthetic CQDs are in an outstanding colloidal state. When photoexcited at 320 nm, the dots were found to show blue fluorescence at 398 nm with a fluorescence quantum yield of 3.32%, long fluorescence decay time, high photostability, and good sensing for hydrogen peroxide. Additionally, the effect of ionic strength was evaluated.