The synthesis of fluorescent carbon quantum dots for tartrazine detection in food: a novel one-step microwave heating approach

Nowadays, carbon quantum dots (CDs) as semiconductor synthesized nanoparticles have become an attractive subject for lots of applications due to their remarkable features. In the current study, the highly fluorescent (FL) CDs with great characteristics were synthesized through a novel one-step microwave irradiation by citric acid monohydrate and urea as carbon precursors. The as-prepared CDs were quasi-spherical shape with an average diameter of 4.5 nm and emitted bright blue FL under ultraviolet light irradiation (UV). Furthermore, the synthesized CDs possessed different properties such as diverse functional groups, good sensitivity and selectivity, high water-solubility, low toxicity, and significant stability in various environmental conditions. The results indicated that the as-prepared CDs can be applied as a fluorescent probe for detection of different concentrations of tartrazine from 5 to 100 µM in food samples. In addition, the findings revealed that the good linear relationship was obtained between the FL intensity of CDs and different concentrations of tartrazine over the range of 5 to 100 µM with the detection limit of 2.58 µM.