Nitrogen-Doped Carbon Dots Enhanced Hydrogen Carbonate-Hydrogen Peroxide Chemiluminescent Reaction and its Application in Ascorbic Acid Sensing

Nitrogen-doped carbon dots (N-CDs) were prepared by self-exothermic procedure using grasshopper powder as a single precursor. The prepared N-CDs not only have excellent fluorescence properties, but also can catalyze and enhance the ultra-weak chemiluminescence of NaHCO₃-H₂O₂. The reaction conditions of NaHCO₃-H₂O₂-N-CDs CL were optimized. Under the optimal experimental conditions, when AA was added to the NaHCO₃-H₂O₂-N-CDs CL system, AA had a significant inhibitory effect on the CL intensity of NaHCO₃-H₂O₂-N-CDs. There was a good linear relationship between the calculated lg(I0/I) and the concentration of AA (C), and the calibration curve equation was lg(I₀/I) = 0.03667 C-0.00708 (µM). The established CL analysis method has a detection limit of 0.12 µM for AA and a linear range of 0–50 µM. The selectivity of CL method was evaluated, and the method was successfully applied to the determination of AA in vegetable and fruit samples. The spiked recoveries were between 88.9% and 118.9%, which indicated that the method was simple, rapid, and sensitive, and had great potential in the determination of AA in foods.