Preparation of bright blue fluorescent carbon dots and their application in highly sensitive chlorogenic acid detection

In this work, bright blue fluorescent carbon dots (CDs) were synthesized through a hydrothermal method by using L-phenylephrine as carbon source. Under exciting at 363 nm, the prepared CDs emitted bright blue fluorescence at 457 nm. The fabricated CDs showed outstanding salt tolerance, temperature stability and good resistance to photobleaching. Interestingly, the fluorescence of CDs could be distinctly quenched by chlorogenic acid (CGA). By using CDs as fluorescent probe, a novel fluorescence method for highly sensitive detection of CGA was established with a wide linear range of 0.1-220 μM and a limit of detection (LOD) as low as 33 nM. The response mechanism was also studied. The method has been successfully applied for the detection of CGA content in three samples of honeysuckle, coffee beans and Eucommia ulmoides leaves with satisfactory recoveries.