Synthesis and applicability of new colorimetric and fluorimetric sensors for toxic thiophenol detection via SNAr

Chemical Biological Radiological Nuclear (CBRN), which is present in every aspect of life, has been used many times in history. Although it is not yet known how people discovered its use and how they first used it, it is encountered in many events and in many areas. For example, during the Tatar occupation of the city of Kaffa, the contamination of the city waters by throwing dead people infected with plague into them, and the subsequent deaths of many people due to plague (Erkekoğlu and Koçer-Gümüşel 2018) is a good example for us. Today, with the development of technology, the number of CBRN agents used and the potential for use and their toxicity values have also increased. Thiophenol (PhSH), which we used in our study and whose chemical formula is C6H5SH, is also an industrial waste with high toxicity. Widely used in many industries, PhSH poses significant health risks due to its acute toxicity and irritant effects. Therefore, PhSH detection is of great importance for ensuring environmental and food safety. In this thesis, we synthesized and characterized two novel sensors (NS1 and NS2) with red/blue fluorescence emission for PhSH detection. After PhSH reacts, NS1 exhibited a low detection limit (66,7 nM) with a fast response time of only 10 seconds and a large Stokes shift (240 nM) of red emission. NS2 was able to detect PhSH with a low detection limit (75,8 nM), a fast response time of 20 seconds and blue emission. The remarkable color response and portability of the two receptors made them suitable for in situ detection of PhSH in a variety of samples such as water, soil, plants, food samples and living cells. Furthermore, it was demonstrated that these receptors can be used to determine PhSH content in smartphone applications, thin layer chromatography kits and polysulfone capsule kits. The prepared receptors were found to have low cytotoxicity and showed good permeability in the live cells tested, which is important for early detection, disease investigation and immediate analysis. Compared to other studies, the proposed approach has notable advantages in terms of limit of detection, portability, response time and low cytotoxicity. Thus, it meets many demands for ensuring health, environmental and food safety and compliance with regulatory standards