微波一步法制备氮掺杂碳点及其用于多巴胺的检测研究

以柠檬酸为碳源,尿素为氮源,采用微波一步法制备得到稳定性高,水溶性好的蓝色荧光的氮掺杂碳点。并将该氮掺杂碳点经透射电子显微镜(TEM)、原子力显微镜(AFM)、X-射线光电子能谱(XPS)和红外光谱(IR)表征,发现其粒径为0.5~5nm,平均粒径2.6nm,富含羟基、羧基和氨基等官能团。在优化实验条件下,多巴胺浓度在2.5~37.5μmol/L范围内与N-CDs的荧光猝灭效率(IF/IF0)呈良好的线性关系,方法的检出限为0.08μmol/L。采用该方法对正常人尿液中的多巴胺进行测定,其加标回收率为99.5%~106%,RSD为1.8%~2.3%,方法准确度高,结果满意。

Preparation of Nitrogen Doped Carbon Quantum Dots by Microwave One-step Method and Their Application in Dopamine Detection

A kind of nitrogen doped carbon quantum dots (N-CDs ) with high stability,good water solubility were prepared by one-step microwave method with citric acid as carbon source and urea as nitrogen source.The prepared N-CDs were characterized by transmission electron microscopy (TEM ),atomic force microscopy (AFM ),X-ray photoelectron spectroscopy (XPS ) and infrared spectroscopy (IR ).Results showed that the N-CDs contained a particle size ranging from 0.5 nm to 5 nm with an average particle size of2.6 nm,which were rich in hydroxyl,carboxyl and amino groups and other functional groups.The N-CDs were used in the detection of dopamine.Under the selected experimental conditions,there was a good linear relationship for the fluorescence quenching efficiency ( I F/ I F 0 ) of N-CDs with dopamine within the concentration range of2.5-37.5 μmol/L,and the method detection limit was 0.08 μmol/L.This method was applied in the detection of dopamine in urine of normal people with high accuracy and satisfactory results.The average recoveries ranged from 99.5 % to106 % with relative standard deviations (RSDs ) of1.8 %-2.3 %.