以生物质黑枸杞为前驱体,采用一步水热法制备出荧光碳量子点材料.通过红外光谱、X射线衍射(X-Ray dif-fraction,XRD)、EDS(Energy Dispersive Spectrometer)能谱、核磁共振波谱、紫外-可见吸收光谱、荧光光谱等对碳点的结构、尺寸、化学组成及光学特性进行了表征.结果表明,合成的碳点有类似石墨烯量子点的晶面结构,尺寸分布在 1~3nm之间,表面存在大量氨基、羧基、羟基等水溶性基团,具有良好的水溶性.碳点溶液在365 nm紫外光照射下呈明亮的蓝色荧光,其荧光量子产率为34.46%,且有着较好的光学稳定性.基于Hg2+、Ag+对碳点的快速、选择性猝灭,建立了定量测定水中Hg2+、Ag+含量的新方法,其检测限分别为36.97 μM和27.04 μM.该碳点溶液还可应用于多种基质表面的潜指纹快速显现,为刑侦领域和案件侦破等方向提供了多种可能.
Fluorescent carbon quantum dots were prepared by one-step hydrothermal method using biomass Lycium ruthenicum berries as precursor.The structure,size,chemical composition and optical properties of carbon dots were characterized by infrared spectrosco-py,X-ray diffraction(XRD)spectrum,energy dispersive spectrometer(EDS)energy spectrum,nuclear magnetic resonance spectrum,UV/Vis absorption spectra and fluorescence emission spectra.The results showed that the synthesized carbon dots had a similar crys-tal structure to that of graphene quantum dots,and the size distribution was between 1 nm~3 nm.There were a large number of wa-ter-soluble groups such as amino,carboxyl and hydroxyl groups on the surface of carbon dots,which made for good water solubili-ty.The carbon dots solution had good optical stability and showed bright blue fluorescence under 365 nm ultraviolet light irradia-tion.Its quantum yield was 34.46%.Based on the rapid and selective quenching of carbon dots by Hg2+and Ag+,a new method for the quantitative determination of Hg2+and Ag+in water was established.The limits of detection were 36.97 μM and 27.04 μM,re-spectively.The carbon dots solution could also be applied to the rapid appearance of latent fingerprints on a variety of substrate sur-faces,providing a variety of possibilities for the field of criminal investigation and case detection.