荧光探针用于食品添加剂定量分析的实验设计

为了让学生掌握荧光分光光度计的使用方法，了解如何采用荧光传感器对食品添加剂进行定量分析，设计了一个研究型的综合实验。基于食品添加剂胭脂红对石墨烯量子点（GQDs）的荧光猝灭作用，在考察溶液酸度和孵育时间对猝灭反应影响的基础上，建立胭脂红浓度与石墨烯量子点荧光强度变化的关系曲线，并对购得的饮料溶液中胭脂红含量进行了定量分析。在实验过程中引入机理讨论，不仅能拓宽学生的知识面，而且能提高学生解决实际问题的能力。本实验集科研性和趣味性于一体，使学生体会到科研的乐趣，激发学生的学习兴趣。该实验操作简单、易行，适用于本科生的综合实验能力训练。

The Experimental Design of Fluorescence Sensor on the Quantitative Analysis of Food Additive

In order to let students master how to use fluorescence spectrophotometer, and how to apply fluorescence sensor on food additives quantitative analysis, a research-oriented synthetical experiment has been designed. Based on fluorescence quenching effect of food additive Ponceau 4R on the fluorescence emission intensity of graphene quantum dots(GQDs), and the effect of pH and incubation time on this quenching reaction, relationship curve between concentrations of Ponceau 4R and variety of fluorescence emission intensity of graphene quantum dots was obtained, furthermore the concentration of Ponceau 4R in beverage was analyzed. Reaction mechanism has been introduced into the experiment process, which not only can wide knowledge of students, but also can improve their ability of solving practical problems. This interesting scientific experiment could encourage and waken study interest of students. And this experiment is simple, easy and suitable for undergraduate's synthetical experiment capability training.