Synthesis And Properties Of Colorimetric-fluorescent Dual-channel Sensors Based On Diarylethene

In recent years,colorimetric and fluorescent detection methods have been widely reported,due to their excellent response,good selectivity,high sensitivity,low cost,and easy of operation compared with those traditional analytical methods.Among the many reported colorimetric and fluorescent chemical sensors,diarylethene-based colorimetric and fluorescent sensors have attracted the attention of many researchers.This is because the diarylethene compounds have superior properties over other photochromic materials,such as excellent thermal stability,remarkable fatigue resistance and fast response,etc.,known as the most promising photochromic material.However,most diarylethene sensors can only identify one analyte by one analytical method,those can simultaneously detect target-analytes by both colorimetric and fluorescent methods are still rare.On the other hand,monitoring multiple targets with a single receptor is not only more efficient but also reduces the cost compared to a one-to-one analysis method.Therefore,we are always working to design simple,efficient and cost-effective colorimetric/fluorescent sensor based on diarylethene,which not only have ionic responses,amino acid responses,or photoresponses.The main contents of this paper are as follows:In chapter one,the concept and recognition mechanism of colorimetric and fluorescent chemical sensors have been summarized,as well as the research progress of colorimetric and fluorescent sensors of diarylethene.Based on these facts,the research content of this paper was proposed.In chapter two,design and synthesis of diarylethene sensor DT-1O modified with 8-hydroxyquinoline-2-carbaldehyde group.UV and fluorescence spectroscopy show that DT-1O has good photochromism and fluorescence switching performance.Besides,DT-1O can specifically detect Hg²⁺through colorimetric/fluorescent analysis methods with high sensitivity and good anti-interference performance.Additionally,the complexation mechanism of DT-1O and Hg²⁺was further verified by mass spectrometry and ¹H NMR.In chapter three,design and synthesis of diarylethene sensor DT-2O modified with 2-?methylthio?benzenamine group.UV spectroscopy exhibited that DT-2O has good photochromism and fatigue resistance,and DT-2O can be used for specific colorimetric recognition of Cu²⁺with good anti-interference performance.In addition,it was found by fluorescence spectroscopy that DT-2O has high sensitivity and high selectivity for Zn²⁺.The pH effect test found that the ideal range for detecting Cu²⁺and Zn²⁺by DT-2O was 7-11 and 8-10,respectively.The complexation of DT-2O with Cu²⁺and Zn²⁺was further verified by mass spectrometry and ¹H NMR titration,and it showed different ways of complexing.In chapter four,design and synthesis of diarylethene sensor DT-3O modified with 4-hydroxy-3-aminocoumarin group.UV absorption spectroscopy studies show that DT-3O has good photochromic properties,and it had highly selective for Arg and Cu²⁺.It is worth noting that Arg and Cu²⁺cause different changes in the UV absorption spectrum and corresponding solution color of DT-3O.Fluorescence spectroscopy indicates that it can be used for the specific detection of Al³⁺.The addition of Al³⁺can increase the fluorescence intensity of DT-3O by 106 folds.Competitive experiments further show that it has great anti-interference performance for Al³⁺recognition.In addition,DT-3O's detection limit for Al³⁺was as low as 8.5nM,which can be successfully used for the detection of Al³⁺in real water samples with satisfactory results.