Use of Carbon Dots Synthesized from Citrate as a Fluorescent Probe for Quercetin Determination in Tea and Beer Samples

Abstract

In this work, carbon dots (CDs) prepared by a one-step hydrothermal method were employed for the determination of quercetin in teas and beers. The fluorescence quenching of CDs was proportional to the concentration of quercetin. Under optimum experimental conditions, linear quenching was observed for quercetin in the range of 1.0 to 10 mg L-1 (F/F 0 = (0.1511 ± 0.0075)[Q] + (0.8922 ± 0.0384), R 2 = 0.9926), at room temperature, using 80 μL CDs and 0.1 mol L-1 Na 2 HPO 4 /NaOH buffer solution (pH 11.0). A limit of detection (3σ criterion) of 0.85 mg L-1 , and a relative standard deviation of 0.21% (n = 3) for 4.0 mg L-1 quercetin solution was obtained. Addition and recovery tests with tea and beer samples were performed resulting in recoveries at the range between 80 and 118%. This procedure served successfully to determine quercetin in beer and tea samples presenting high sample throughput.

Inhibitory effects of iron-based carbonaceous nanocomposites on mushroom tyrosinase activity: molecular aspects and mechanistic insights

“…1d). The π–π* transition (at 230 nm) 41,42 and the aromatic π–π* and carbonyl n–π* transition peaks (at approximately 250–290 nm) 43 were observed in the UV-Vis spectrum of the FeCQDs (Fig. 2b).…”

Biogenic synthesis of carbon quantum dots from garlic peel bio‐waste for use as a fluorescent probe for sensing of quercetin

“…Fluorescence - [44] Carbon dots Fluorescence 0.85 mg/L [62] Gold nanoclusters Fluorescence 1.8 Â 10 À8 mol/L [63] Capillary electrophoresis Electrochemical [64] Graphene modified Glassy carbon electrode (GR/GCE) Electrochemical 3.6 nmol/L [65] Garlic peel bio-assisted carbon quantum dots (CQDs) Fluorescence 6.73 μM Present work sions. [66] The influences of familiar potentially interfering substances such as citric acid, creatinine, agarose, ascorbic acid, asparagine, dopamine and malic acid were tested.…”

Current State of Sensors and Sensing Systems Utilized in Beer Analysis

“…The calibration curve displayed a linear detection range from 0.4 to 9.0 µmol/L with a LOD of 0.12 µM [103]. Fluorescent carbon dots and water-soluble carbon dots synthesized from citrate were also used for quercetin determination [104,105].…”