AUTHOR=Wang Panyong , Zhang Yan , Liu Yulu , Pang Xinpei , Liu Pai , Dong Wen-Fei , Mei Qian , Qian Qing , Li Li , Yan Ruhong TITLE=Starch-Based Carbon Dots for Nitrite and Sulfite Detection JOURNAL=Frontiers in Chemistry VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.782238 DOI=10.3389/fchem.2021.782238 ISSN=2296-2646 ABSTRACT=

Nitrite and sulfite play important roles in human health and environmental science, so it is desired to develop a facile and efficient method to evaluate NO₂^- and SO₃^2- concentrations. In this article, the use of green alternatives with the potential of multi-functionality has been synthesized to detect nitrite and sulfite based on fluorescent probe. The carbon dots (CDs) with starch as only raw materials show fluorescence turn “on-off-on” response towards NO₂^- and SO₃^2- with the limits of detection of 0.425 and 0.243 μМ, respectively. Once nitrite was present in the solution, the fluorescence of CDs was quenched rapidly due to the charge transfer. When sulfite was introduced, the quenching fluorescence of CDs was effectively recovered because of the redox reaction between NO₂^- and SO₃^2-, and thus providing a new way for NO₂^- and SO₃^2- detection. Owing to their excellent analytical characteristics and low cytotoxicity, the “on-off-on” sensor was successfully employed for intracellular bioimaging of NO₂^- and SO₃^2-.