壳聚糖基碳量子点的制备、表征及其对过氧化氢的荧光检测研究

Preparation and Characterization of Chitosan-Based Carbon Dots and Its Application in Hydrogen Peroxide Analysis

为制备可用于分析过氧化氢(H_(2)O_(2))的荧光传感器,本研究利用壳聚糖与DL-酒石酸为反应前体,水热处理制备了新型氮掺碳量子点(CDs),能够高效、简便地检测食品中的H_(2)O_(2)含量;并采用透射电镜(TEM),以及傅里叶变换红外光谱(FTIR)等方法进行分析表征。结果表明,CDs的荧光量子产率约为5.22%,粒径约为20 nm,而且具有石墨烯结构,其表面也含有较丰富的羟基、氨基和羧基等功能性官能团。此外,Fe^(3+)可以猝灭CDs溶液的荧光,而Fe^(2+)几乎不影响;按照CDs与Fe^(3+)混合后荧光几乎消失时的浓度配比,将Fe^(3+)替换成同等浓度Fe^(2+)再分别加入不同浓度的H_(2)O_(2),快速混均后测量其在320 nm激发光下的荧光发射图谱,绘制标准曲线,H_(2)O_(2)浓度在0~60μmol·L^-1内线性关系良好,相关系数R2约为0.9900,检测限约为0.65μmol·L^(-1)。本研究结果为快速检测食品中的H_(2)O_(2)提供了一定的理论依据。

To prepare a fluorescence sensor for cocoa analysis of H_(2)O_(2),chitosan and dl-tartaric acid were used as precursors to prepare novel nitrogen doped carbon quantum dots(CDs)by hydrothermal treatment,which could be used to detect the amount of hydrogen peroxide(H_(2)O_(2))in food efficiently and conveniently.Transmission electron microscopy(TEM)and Fourier transform infrared spectroscopy(FTIR)were used to analyze and characterize.The results showed that the fluorescence quantum yield of the CDs was about 5.22%,and the particle size was about 20 nm,CDs contained a graphene structure with nitrogen atoms,and its surface showed abundant functional groups such as hydroxyl amino and carboxyl groups.In addition,Fe3+can quench the fluorescence of CDs solution,while Fe^(2+)had almost no effect on CDs.According to the concentration ratio of CDs and Fe^(3+)when the fluorescence almost disappeared after mixing,then Fe^(3+)replaced by Fe2+at the same concentration,and then H_(2)O_(2) of different concentrations was added.After the rapid and uniform mixing,the fluorescence emission spectrum under the excitation light at 320 nm was measured and the standard curve was obtained with a linear relationship of H_(2)O_(2) concentration at 0-60 nm,and the correlation coefficient called R2 was about 0.9900,with the detection limit about 0.65 nm.