Solvent-controlled synthesis of full-color carbon dots and its application as a fluorescent food-tasting sensor for specific recognition of jujube species

Full-color luminescent carbon dots (CDs) possess enormous feasible applications in fluorescence sensing. However, the modulation of luminescent emission requires proper synthesis strategies with distinctive precursors to regulate the surface chemistry of the CDs. In this work, the full-color CDs were prepared with the same reactants by adjusting the reaction solvent to cover the entire spectral range. The factors that determined their luminescence caused by solvents were discussed. We found that CDs had a rapid sensing ability to Fe3+ with a wide detection range and high accuracy. Moreover, the discriminant model of jujube species depending on internal Fe3+ content was established successfully using principal component analysis and Bayesian discriminant analysis. This study provides a novel perspective for the preparation of full-color CDs by the same reactants and provides strong application potential in the identification of jujube species by a fluorescent sensor.