Solvothermal Synthesis of Carbon Dots with Alkynyl Ligand for pH and Resveratrol Detection

In the present study, carbon dots (CDs) were synthesized by solvothermal method using 1,4-diethynylbenzene as carbon source. The CDs exhibited the spherical particles as observed from transmission electron microscopy (TEM) image with the average particle size of 2.25±0.51 nm. The fluorescence quantum yield of the final CDs was 13% under excitation at 460 nm. The fluorescence intensity of CDs is diminished at both acidic and basic conditions, while a good linear relationship was realized at pH = 2–7 with the coefficient of determination (R²) of 0.9984 and the minimum detection limit (LOD) of 0.6 with good reversibility and cyclicity for pH detection. trans-resveratrol (t-res) was found to enhance the fluorescence of CDs well and the fluorescence intensity showed a good linear relationship to t-res within the concentration range of 10–100 μM with the coefficient of determination R² of 0.9993 and the LOD of 3 μM. The recoveries of the wines ranged from 100.36–102.40% with the relative standard deviations (RSD) of 2.56–3.48%. Thus, the CDs are extremely sensitive to t-res. Alkynyl ligand is used to prepare CDs, which illustrate the potential application for pH and t-res detection.