碳点荧光探针的制备及其检测金银花中绿原酸含量的研究

Preparation of carbon dot fluorescent probes and study on determination of chlorogenic acid in Lonicerae Japonicae Flos

目的以氯、氮掺杂碳点(Cl/N-CDs)为荧光探针,基于Cl/N-CDs和绿原酸之间的内滤效应,猝灭Cl/N-CDs的荧光,建立了绿原酸荧光检测新方法。方法以氯化胆碱与尿素形成的低共熔溶剂及柠檬酸为原料,通过一步水热法完成碳点制备,并通过透射电子显微镜,紫外-可见分光光度法,红外光谱,X射线衍射,X射线光电子能谱和荧光对其光学性能、形貌及相关基团进行表征。结果绿原酸在0.47~62.70μg/mL对Cl/N-CDs的荧光猝灭呈良好的线性关系,用于金银花提取液中绿原酸的检测,其检出限可达到36 ng/mL。在绿原酸不同提取方法中,以氯化胆碱/尿素低共熔溶剂作为提取剂时对金银花中绿原酸的提取效率最高。结论以低共熔溶剂作为碳点制备原料和绿原酸提取溶剂,可实现绿原酸的提取和检测的双重作用,为金银花的质量评价提供新的研究思路。

Objective In this study,chlorine and nitrogen doped carbon dots(Cl/N-CDs)were used as fluorescent probes.Based on the internal filtration effect between Cl/N-CDs and chlorogenic acid to quench Cl/N-fluorescence of CDs,a new method for fluorescence detection of chlorogenic acid has been established.Methods The Cl/N-CDs was synthesized by one-step hydrothermal method using the eutectic solvent formed by choline chloride/urea and citric acid as raw materials.The optical properties,morphology and related groups of Cl/N-CDs were characterized by TEM,UV-vis,FT-IR,XRD and XPS.Results In the range of 0.47—62.70μg/mL,the fluorescence quenching of Cl/N-CDs by chlorogenic acid showed a good linear relationship,and the detection limit of chlorogenic acid in the extract could reach 36 ng/mL.Among the different chlorogenic acid extraction methods,choline chloride/urea eutectic solvent used as the extractant has the highest extraction efficiency for chlorogenic acid in Lonicerae Japonicae Flos(LJF).Conclusion The eutectic solvent is used as the raw material for carbon dot preparation and the chlorogenic acid extraction solvent,which can play the dual role of chlorogenic acid extraction and detection,and provide new research ideas for the quality evaluation of LJF.