A Highly Selective Fluorescence-Enhanced Probe for the Rapid Detection of SO2 Derivatives and Its Bio-Imaging in Living Cells

Content Provider	Semantic Scholar
Author	Wang, Hongying Chen, Baoquan Zhou, Yaogen Zhou, Yiwei
Copyright Year	2019
Abstract	In this study, we report a simple coumarin-based probe CISD for the detection of SO2 derivatives. In the case of the probe CISD, HSO3 can induce an obvious fluorescence-enhanced response with high selectivity, fast response (within 10 sec) as well as low limit of detection (262 nM). HR-MS experiment revealed the sensing mechanism concerning the nucleophilic addition reaction. Furthermore, the probe CISD has been successfully applied for imaging exogenous HSO3 in living HeLa cells. INTRODUCTION Sulfur dioxide (SO2) is a most common environmental pollutant, and inhaled SO2 can be easily hydrated to sulfurous acid in the respiratory tract, followed by the formation of its derivatives, sulfite and bisulfite (SO3 and HSO3, 3:1 M/M in neutral fluid and plasma).1 Additionally, SO2 derivatives are largely used as preservatives and additives for many drinks, foodstuffs, and pharmaceuticals due to its antimicrobial, bacteriostatic and antioxidant abilities, which make the human exposure to SO2 increasingly widespread. In fact, SO2 can be also endogenously produced during the normal processing of sulfur-containing amino acid in mammals, 2,3 and as a biologically active molecule, it could mediate a wide range of physiological and pathophysiological processes, e.g. having vasorelaxant effect,4 improving myocardial antioxidant capacity,5 ameliorating pulmonary vascular structural remodeling,6 and regulating cardiovascular function,7 etc. Unfortunately, as a double-edged sword, excessive intake of SO2 and its derivatives could also exert very harmful influences on human health. A large number of epidemiological studies have shown that chronic or acute exposure to unregulated amounts of SO2 in the human body may induce many health issues, such as asthma and allergic reactions,8 neurological diseases,9 and even lung cancer.10 To maintain homeostasis in humans, the concentration of SO2 derivatives is tightly regulated. Accordingly, developing simple and highly sensitive methods for the detection and quantitation of SO2 derivatives in environmental monitoring and biological applications is absolutely essential. To date, several methods have been developed for the detection of SO2 derivatives in food and environment, such as chromatography, spectrophotometry, and electrochemical analysis.11-15 However, most of these methods depend on multiple reagents and expensive apparatus, or require complex pre-treatment processes and time-consuming work. Fluorescent probes as an important class of promising technique, have revolutionized our ability to detect and monitor analytes in real-time with excellent selectivity, sensitivity and reproducibility, convenient operating system, high spatial and temporal resolution as well as non-invasiveness and non-destructiveness.16-18 Additionally, probes can also serve the concomitant visualization of distinct analytes and processes.19 In this context, the development of fluorescent probes for the detection of SO2 derivatives represents a very active research field, and many small molecule fluorescence probes with different SO3/HSO3-reactive moiety like aldehyde, double bond and levulinate have been developed.20-26 Nevertheless, there are still some limitations for SO2 probes, e.g. long response time, interference from hydrogen sulfide (H2S), as well as high range of organic cosolvents.27 Thus, further study is urgently needed to develop practical and efficient sensors for sensing SO2 derivatives. Coumarins belong to benzopyrone chemical class and have been considered as promising building blocks for the construction of functional fluorescent probes due to its relatively high quantum yield, high photostability and biological compatibility.28,29 In this work, we proposed a new coumarin-based fluorescent probe CISD for the detection of SO2 derivatives. As shown in Scheme 1, CISD was constructed by the aldol condensation of 3-acetylcoumarin (1) and 2-methylindole-3-carboxaldehyde (2). Owing to the strong nucleophilicity of SO2 derivatives, when the probe CISD is exposed to HSO3, HSO3 can easily attack the C=C bond linking the coumarin and 2-methylindole units in aqueous solution,30 which could cause the change of the electronic distribution and the interruption of the π-conjugation,24 thus leading to a significant fluorescence enhancement and a color change. Scheme 1. Synthetic route of the probe CISD O O
Starting Page	1513
Ending Page	1524
Page Count	12
File Format	PDF HTM / HTML
DOI	10.3987/com-19-14167
Volume Number	98
Alternate Webpage(s)	https://heterocycles.jp/newlibrary/downloads/PDF/26523/98/11
Alternate Webpage(s)	https://doi.org/10.3987/com-19-14167
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article