一步法水热合成枸杞荧光碳点及对Fe^3+的灵敏检测

Green Synthesis of Fluorescent Carbon Nanodots from Chinese Wolfberry for Selective and Sensitive Detection of Ferric Iron

以枸杞为碳源,采用简单、环境友好的一步水热法合成未经表面修饰的荧光碳点。采用紫外-可见吸收光谱、荧光光谱、高分辨透射电子显微镜、傅里叶变换红外光谱和X射线光电子能谱对其性质及形貌进行了研究。在最佳条件下,碳点的激发峰和发射峰分别位于320和400 nm,且发射峰具有尺寸依赖的性质。以罗丹明6G为参照,此碳点的量子产率54%,荧光寿命9.04μs。碳点的荧光在2 min内被Fe^(3+)完全猝灭。基于此,构建了检测Fe^(3+)的新型荧光生物传感器。在1~50μmol/L范围内,荧光猝灭程度与Fe^(3+)的浓度呈良好的线性关系,检出限为232 nmol/L。此碳点在环境和生物医学领域具有良好的应用前景。

Water dispersible fluorescent carbon nanodots(CDs)were prepared by a facile and eco-friendly hydrothermal process using Chinese wolfberry as precursor without any further surface modification.The obtained CDs were characterized by UV-visible absorption spectroscopy,fluorescence spectroscopy,high-resolution transmission electron microscopy,Fourier transform infrared and X-ray photoelectron spectroscopy.It showed emission spectrum of blue which located at 400 nm with excited wavelength of 320 nm.High quantum yield of 54%,long lifetime of 9.04μs,and good biocompatibility were also observed.Importantly,the fluorescence intensity of CDs was selectively quenched within 2 min after addition of Fe^3+.Based upon the phenomenon,a new fluorescent biosensor for detection of Fe^3+was proposed.No significant interference from other metal ions was observed.The linear range and detection limit for Fe^3+was 1-50μmol/L and 232 nmol/L(3σ),respectively.These superior properties demonstrated that the synthesized CDs had promising applications in the fields of environmental and biomedical science.