生物质衍生荧光碳点高灵敏检测环境水样中四环素

Highly Sensitive Detection of Tetracycline in Environmental Water Samples by Biomass-Derived Fluorescence Carbon Dots

以生物质材料海带为碳源,通过水热法一步合成了氮掺杂的碳点(N-CDs)。制备的碳点呈球型,平均粒径约为3.4 nm。最佳激发波长为302 nm,发射波长为369 nm。N-CDs的激发或发射光谱与四环素的紫外吸收光谱均有比较大的重叠,N-CDs与四环素之间可能形成了内滤效应,导致N-CDs的荧光猝灭。考察了溶液pH和反应时间对荧光猝灭效果的影响,在最佳条件下,该体系的荧光猝灭强度与四环素的浓度在1.25~21.25μmol/L的范围内呈现良好的线性关系,线性方程为:(F_(0)-F)/F_(0)=0.02291cTC(μmol/L)+0.06244,线性相关系数R^(2)=0.9920,检出限为0.28μmol/L。该方法成功用于湖水中四环素含量的测定,加标回收率为96.3%~103.8%,相对标准偏差为0.40%~3.0%。

Nitrogen doped carbon dots(N-CDs)were synthesized via one step hydrothermal method using kelp as carbon source.The N-CDs were spherical with an average particle size of 3.4 nm.The maximum excitation and emission wavelengths were 302 nm and 369 nm,respectively.The excitation or emission spectrum of N-CDs overlapped with the UV absorption spectrum of tetracycline,the inner filter effect might be formed between N-CDs and tetracycline,resulting in fluorescence quenching of N-CDs.The effects of pH and reaction time on the fluorescence quenching were investigated.Under the optimal conditions,the fluorescence quenching intensity of the system showed a good linear relationship with the concentration of tetracycline in the range of 1.25-21.25μmol/L,and the linear equation was as follows,(F_(0)-F)/F_(0)=0.02291CTC(μmol/L)+0.06244,the linear correlation coefficient(R^(2))was 0.9920,and the detection limit was 0.28μmol/L.The method was successfully applied to the detection of tetracycline in lake water,the recoveries were 96.3%-103.8%with relative standard deviations of 0.40%-3.0%,and the results were satisfactory.