The study of flavonoid interaction with carbon quantum dots (CDQs) as the basis for the fluorometric point-of-need flavonoid quantification
Author : Valeriia Tishchenko, Zaitsev V., Vakhitov T.
Abstract :The quantification of flavonoids is needed for various products, including raw plant materials, foods, pharmaceuticals, cosmetics, perfumes and the by-products of various industries. The conventional colorimetric method for measuring total flavonoid content by use of Al3+ salts is inexpensive and easily performed, but its results depend on the chemical structure of the analytes. We studied the interactions between two kinds of carbon quantum dots (CQDs), and a selection of flavonoids alone and in complex with Al3+. Fluorescent CQDs were produced by the microwave-assisted method from L-cystein (cys CQD with blue emission) and from citric acid and urea (curCQD with green emission). Quercetin, rutin (quercetin-3-O-rutinoside) and taxifolin (dihydroquercetin) were used as analytes at concentrations of 0.01-1 µM. Quercetin and rutin caused effective quenching of visually detected CQDs f luorescence at concentrations of 0.1-0.3 µM for cys CQD or 0.3-0.5 µM for cur CQD. The quenching action of taxifolin is markedly lower than of quercetin or rutin. Aluminium chloride prevented quenching of CQDs f luorescence and caused a right shift of emission spectra in triple complexes CQD+quercetin+Al3+ at excitation wavelengths of 365 nm. We suppose that this effect can be due to the Förster resonance energy transfer (FRET) from CQDs to quercetin+Al3+ complex. Both the CQDs fluorescence quenching by flavonoids and FRET-mediated emission wavelength shift could be used for the non-instrumental f luorometric point-of-need flavonoid quantification
Keywords :Flavonoid Quantification, Carbon Quantum Dots, Fluorescence Quenching, Förster Resonance Energy Transfer (FRET), Quercetin, Rutin, Taxifolin, Aluminium Complex, Microwave-Assisted Synthesis
Conference Name :International Conference on Agriculture, Forest, Food, Food Sciences and Technologies (ICAF3T - 25)
Conference Place Plovdiv, Bulgaria
Conference Date 24th Dec 2025
