水热法新型水溶性荧光碳点的制备及其性能研究

Study on Preparation and Properties of Water Soluble Fluorescent Carbon Dots by Hydrothermal Method

以阿拉伯糖和磷酸酪蛋白肽进行水热反应,制备水溶性多色荧光碳点,利用透射电子显微镜(TEM)、紫外吸收光谱(UV)、荧光光谱(FL)、红外光谱(FTIR)和X射线衍射(XRD)等对所制备碳点的粒径大小、吸收光谱、发光性质、表面基团等进行表征,并考察了其性能和对不同金属离子的识别作用。结果表明:制备的荧光碳点平均粒径为4.62 nm,其紫外最大吸收波长为281 nm,XRD峰值约为21°,可在紫外灯下发出明亮的荧光,最大发射波长为414 nm,且呈荧光多元发射。红外光谱分析表明存在—COOH,—NH2和—OH基团。该荧光碳点具有良好的性能,且对Cu2+和Fe3+有较强的选择性识别作用,其原因可能是荧光碳点的聚合导致粒径增大从而使荧光强度减弱。该碳点有望作为荧光探针用于检测分析和生物成像等领域。

The water soluble carbon dots were prepared by hydrothermal reaction with arabia sugar and casein phosphopeptides. Transmission electron microscopy （TEM）, ultraviolet absorption spec- troscopy （ UV）, fluorescence spectroscopy （FL） and infrared spectroscopy （FTIR） and X-ray diffrac- tion（XRD） were used to characterize the particle size, absorption spectra, luminescence properties and surface groups of the carbon dots. The FL intensity changes in the presence of representative met- al ions under the same conditions were investigated to evaluate the selectivity of the carbon dots. The results showed that the average particle size of the fluorescent carbon dots is 4.62 nm, and its maxi- mum absorption wavelength is 281 nm. The fluorescent carbon dots could emit bright fluorescence in the ultraviolet light with maximum emission wavelength of 414 nm. The carbon dots have good water solubility, and the fluorescence emission spectrum is red shift with the increase of the excitation wavelength. FTIR spectra analysis revealed the presence of--COOH, --NH2 and --OH groups are on the surface of the carbon dots, and the XRD peak is about 21 °. Tremendous FL intensity decrease was observed by addition of Cu^2＋ and Fe^3＋ The reason may be that the ions caused the aggregation of the fluorescent carbon dots, leading to the decrease of fluorescence intensity. The carbon dots are expected to be used as a fluorescent probe for analysis and biological imaging.