制备生物质氮掺杂碳点及检测硫普罗宁

Preparation of biomass N-doped carbon dots and detection of tiopronin

通过一步水热合成法,以石榴籽为碳源,尿素为氮源,制备得到了氮掺杂碳点(N-CDs)。通过透射电镜(TEM)观察到N-CDs平均粒径为20 nm;原子力镜(AFM)确定N-CDs厚度为0.6~1.4 nm;傅里叶红外光谱(FT-IR)证明N-CDs表面氨基等水溶性官能团的存在。以制备获得的N-CDs作为目标荧光团,Hg^(2+)可高效结合到N-CDs表面形成络合物,并实现静态猝灭。而加入硫普罗宁可结合络合物中的Hg^(2+),使其脱离N-CDs表面,实现荧光恢复。由此建立的荧光开关检测硫普罗宁方法,较传统检测方法更准确灵敏。通过优化pH、反应时间、N-CDs和Hg^(2+)的用量确定最佳条件。实验测得相对偏差(RSD)为4.7%,检出限为0.2μmol/L。采用此方法对人血清实际样品中的硫普罗宁含量进行测定,回收率为97.2%~101.3%。

Nitrogen-doped carbon dots(N-CDs)were prepared by one-step hydrothermal synthesis with pomegranate seeds as the carbon source and urea as the nitrogen source.Observed by transmission electron microscopy(TEM),average particle size of N-CDs was 20 nm.Observed by atomic force microscopy(AFM),the thickness of N-CDs was 0.6-1.4 nm.Fourier transform infra-red(FT-IR)confirmed the presence of water-soluble functional groups such as amino groups on the surface of N-CDs.With the prepared N-CDs as the target fluorophore,Hg^(2+)can efficiently bind to the surface of N-CDs to form a complex,and achieve static quenching.The addition of tiopronin can bind the Hg^(2+)in the complex to make the Hg^(2+)detach from the surface of N-CDs and realize fluorescence recovery.The nano fluorescence switch constructed in this work is more accurate and sensitive than the traditional detection method.The optimum conditions were determined by optimizing the pH value,reaction time,the dosage of N-CDs and Hg^(2+).The relative deviation(RSD)was 4.7%,and the detection limit was 0.2μmol/L.The method was used to determine the content of tiopronin in human serum samples with the recoveries of 97.2%-101.3%.