Sulfur and nitrogen doped fluorescent carbon dots as well as preparation method and application thereof

The invention relates to a sulfur-nitrogen doped fluorescent carbon dot as well as a preparation method and application thereof, the carbon dot is used as a fluorescent probe, and the addition of Cr (VI) can quench fluorescence through an inner filter effect; based on the oxidation-reduction reaction process, the addition of ascorbic acid or sulfur ions enables the fluorescence of the carbon dot/Cr (VI) system to recover. According to the method, fluorescence'closing 'and'opening' detection can be realized without other conditions, and the method is simple to operate and good in sensitivity and has a good application prospect. 本发明涉及一种硫氮掺杂荧光碳点及其制备方法和应用，本发明碳点作为荧光探针，Cr(VI)的加入会通过内滤效应使荧光猝灭；基于氧化还原反应过程，抗坏血酸或硫离子的加入又使得碳点/Cr(VI)体系荧光恢复。本发明无需其他条件就可以实现荧光"关闭"和"开启"检测，且操作简单，灵敏度良好，具有良好应用前景。