Synthesis And Properties Of Fluorescent Probes Based On Phenothiazine Derivatives For The Detection Of Hypochlorous Acid And Sulfur Dioxide

Fluorescent probes are analytical tools that can detect target analytes quickly and sensitively,making outstanding contributions to environmental and biological analysis.Given the expanding development of the field,fluorophore plays a key role in the design of fluorescent probes.Compared with classical fluorophore,phenothiazine compounds with electron-rich properties have higher pharmacological and biological activities,and have attracted wide attention in many fields of chemistry,biology and medicine.They are also converted into antioxidants in industrial lubricants and fuels,photoelectric materials（such as organic light-emitting diodes）,biomedicine（with a variety of biological activities,Such as antibacterial,antifungal,anticancer,anti-inflammatory,etc.）and dyes.In the first chapter,the composition and main recognition mechanism of fluorescent probes are summarized briefly.The research progress of fluorescent hypochlorite probe and sulfur dioxide probe are described in detail.The fluorescence probes based on phenothiazine derivatives are discussed in detail.On this basis,the research topic of this paper was put forward,that is,three kinds of fluorescent probes for hypochlorous acid detection were synthesized using phenothiazine derivatives as the matrix,and the spectral test and application of the probes were carried out.In Chapter 2,a fluorescence probe TF with both ultraviolet and fluorescence response to ClO^-was synthesized by connecting diamino-maleonitrile to phenothiazine derivatives to form Schiff base structure.The photophysical properties of the probe were studied,and the mechanism of the reaction between the probe and ClO^-was verified.The ability of the probe to detect ClO^-in real water samples,test paper and cell imaging was investigated..In Chapter 3,we designed and synthesized a new fluorescence probe LD-Lyso for the detection of ClO^-by colorimetric ratio of phenothiazine and coumarin derivatives.Firstly,its structure was characterized by ¹H NMR,¹³C NMR,FT-IR and ESI-MS.Then,the selectivity,anti-interference,sensitivity,time response and pH dependence of LD-Lyso to ClO^-in PBS buffer solution were investigated,and its recognition mechanism was analyzed,and it was applied to the detection of ClO^-in real water samples and test strips.In Chapter 4,we designed and synthesized a new fluorescence probe SN,which can detect both HClO and SO₂,and has a good linear relationship.Probe SN has two reaction sites:（1）phenothiazine is sensitive to HClO;（2）benzopyran salt is the recognition group of SO₂.In CH₃CN/PBS solution（v/v=7/3,pH=7.4）,little fluorescence was found in probe SN.The presence of HClO oxidizes the phenothiazine part of the probe SN,which greatly reduces it electron-giving ability,thus leading to the opening of green fluorescence.The presence of SO₂attacks the C=C double bond portion of the benzopyrane salt,causing the red fluorescence to turn on.Its structure was characterized by ¹H NMR and ESI-MS,and its sensing mechanism on HClO and SO₂was systematically studied.