红色荧光碳点的制备及其对过硫酸根的检测

以对苯二胺为碳源,乙醇为溶剂,采用溶剂热法合成红色荧光碳点(R-CDs)。 通过透射电子显微镜、紫外可见吸收光谱(UV-Vis)、红外光谱(FT-IR)、X射线光电子能谱(XPS)对其进行表征。 合成的R-CDs粒径约为(3.63±0.20) nm。 R-CDs的最大激发和发射波长分别为480和620 nm,具有激发波长独立性,光稳定性好。 基于静态猝灭,R-CDs的荧光可以被过硫酸根(S₂O₈^2-)有效猝灭。 在2.5~120 μmol/L范围内,S₂O₈^2-的浓度与R-CDs的荧光猝灭程度呈线性关系,相关系数(R²)为0.9970,检出限为1.2 μmol/L,具有良好的选择性和高灵敏度。 同时,该荧光传感体系可应用于自来水和湖水样品中S₂O₈^2-的检测。

Synthesis of Red Emission Fluorescent Carbon Dots and Its Application for Detection of Persulfate

Red fluorescent carbon dots (R-CDs) were synthesized by one-step solvothermal method by using p-phenylenediamine and ethanol. The synthesized R-CDs were characterized by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy, respectively. The results indicate that the R-CDs are uniform with an average size of (3.63±0.20) nm. Abundant groups like hydroxyl and amine groups are linked on the surface of the synthesized R-CDs. The as-prepared R-CDs show excitation-independent property and the maximum excitation and emission wavelengths are 480 and 620 nm, respectively. Based on static quenching between R-CDs and persulfate, the fluorescence of R-CDs could be effectively quenched by persulfate. A fluorescent strategy is developed for detection of persulfate. The method showed a linear range of 2.5~120 μmol/L with a correlation coefficient (R²) of 0.9970. The limit of detection was 1.2 μmol/L, showing excellent sensitivity and selectivity. Meanwhile, the as-proposed sensing system is successfully applied to the analysis of persulfate in tap water and lake water samples with satisfactory results.