A novel and visible ratiometric fluorescence determination of carbaryl based on red emissive carbon dots by a solvent-free method

In this study, a simple and effective ratiometric fluorescence method has been developed for carbaryl detection, utilizing red emissive carbon dots (R-CDs). The underlying principle of this proposed strategy relies on the rapid hydrolysis of carbaryl under an alkaline condition and production of 1-naphthol with blue-emission at 462 nm. Furthermore, the as-synthesized R-CDs (Em. 677 nm), serve as a reference, enhancing the visual tracking of carbaryl through the transformation of fluorescent color from red to blue. The concentration of carbaryl exhibits a commendable linear correlation with the ratio of fluorescence intensity, ranging from 0 to 20 mu g/mL ( R2 = 0.9989) with a low detection limit of 0.52 ng/mL. Additionally, the described methodology can be used for the enzyme-free visual assay of carbaryl, even in the presence of other carbamate pesticides and metal ions, in tap water and lake water samples with excellent accuracy (spiked recoveries, 94 %-106.1 %), high precision (relative standard deviation (RSD) <= 2.42), and remarkable selectivity. This fast and highly sensitive naked-eye ratiometric sensor holds immense promise for carbaryl detection in intricate environments and food safety fields. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.