Preparation of Nitrogen-Doped Carbon Quantum Dots and Analysis and Detection Of Vitamin B2

Abstract

This paper focuses on the preparation of Nitrogen-doped carbon quantum dots (N-CQDs) from citric acid and urea, and their application in the detection of vitamin B2. Citric acid was used as the carbon source and urea as the nitrogen source. N-CQDs were prepared by heating, after which they displayed excellent fluorescence performance and stability. The structure of the sample was then characterized using UV-visible spectrophotometry, fluorospectrophotometry, and Fourier transform infrared spectroscopy. Optimal pH, ultrasonic reaction time, and vitamin B2 concentration for the N-CQDs were studied and optimized. Under optimal conditions (50 μL of N-CQDs, 2 mL of buffer solution with pH 4.0, and a reaction time of 30 min), the analysis and detection using fluorospectrophotometry demonstrated that vitamin B2 caused significant fluorescence quenching of the prepared N-CQDs. With the standard recovery rate above 80%, these N-CQDs can serve as fluorescence probes for the analysis and detection of vitamin B2 in actual food.