Bioresource-derived multifunctional carbon quantum dots as a fluorescence and electrochemical sensing platform for picric acid and noncytotoxic food storage application

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2023, 126(0), , pp.546-556
• Main Authors: John, Bony K., Thara, Chinnu R., Korah, Binila K., John, Neenamol, Mathew, Beena
• Format: Article
• Language: English
• Subjects: Antioxidant; Carbon quantum dots; Electrochemical sensing; Fluorescence sensing; Picric acid; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2023.06.043

[Display omitted] This work deals with the synthesis of facile, water-soluble, and blue-emitting carbon quantum dots (CQDs) from Plumbago indica leaves by a hydrothermal method with a quantum yield of 16 %. The biomass Plumbago indica leaves exhibit several advances such as easy availability, cost-effectiveness, non-toxic, green source, and not requiring any sophisticated techniques to develop the sensor. The optical, morphological, structural, and compositional properties of the CQDs were confirmed by various characterization methods. As a fluorescent probe, CQDs exhibited good linear response to picric acid (PA) with a limit of detection (LOD) of 18 nM. The sensing mechanism involves a combination of static quenching and fluorescence resonance energy transfer (FRET). In the electrochemical sensing method, the differential pulse voltammetric (DPV) technique was performed using a CQD-modified gold electrode with a LOD of 0.35 nM for PA. Using fresh carrots as a model sample, the antioxidant activity of PVA, CQD, and a PVA-CQD mixture was qualitatively determined. The in vitro cytotoxicity analysis of CQDs by MTT assay using the L6 cell line confirmed its non-toxic behaviour. This work is noteworthy because it offers a new attempt to identify toxic PA from biomass-derived precursor material and finds future applications in the food industry.