| The cyanine dyes have the advantages of high molar absorption coefficient,high fluorescence quantum yield,low background interference,and can be used for red-near infrared zone detection,so that it has a high selectivity and sensitivity in the assay.As the superior performance of cyanine dyes,a series of derivatives which were widely used in molecular biology and chemical analysis etc,and the research and application of molecular probes based on cyanine dyes have also become one of the hotspots.This paper was based on the previous research work,with the cyanine dyes as matrix,successful designed and synthesised of three molecular probes and applied to the detection of mercapto amino acids and neurotoxic analysis,phosgene.And this paper consists of four chapters.In chapter 1,introduction.Firstly,the basic concepts and design principles of optical molecular sensors were briefly introduced;Secondly,the structural characteristics,performance characteristics and application of cyanine dyes were summarized;And then,the research status and development prospect of mercapto amino acid,diethylphosphoryl chloride and phosgene molecular probes were mainly introduced;Finally,summarized these related research and combined the existing conditions and working basis of our laboratory,put forward the research of this paper.In chapter 2,based on the mechanism of nucleophilic substitution of mercapto amino acid,we successfully designed and synthesized and studied on the spectral characteristics of the heptamethyl cyanine probe containing the resorufin substituents as the optical molecular sensor of the mercapto amino acid.First,the resorufin group in the probe molecule is substituted with a mercapto group in the mercaptoamino acid(GSH,Cys,Hcy)to produce thiocyanine and release the fluoro-fluorophore.Then,for cysteine/homocysteine(Cys/Hcy),the resulting thiocyanine undergoes intramolecular rearrangement to form amino cyanine.And finally leaded to the probe molecules show different spectral characteristics and thus could be selectively identified GSH and Cys/Hey these two kinds of mercapto-containing amino acids.This probe had a high sensitivity and could be used for naked eye detection,and because of its detection wavelength located in the near infrared region,would greatly reduce the interference of other biomolecules or matrix background.In chapter 3,designed and synthesised of ketone cyanine as the probe matrix,based on seven methyl cyanine ketone-enol conversion of diethyl phosphoryl chloride(neurotoxic low toxicity mimetic)molecular probe.Due to the characteristics of phosphorylation reaction of diethylphosphoryl chloride,the two tautomers of the above-mentioned cyanine could be controlled by diethylphosphoryl chloride to achieve the purpose of detecting diethylphosphoryl chloride.The carbonyl group of the probe molecule undergoes phosphorylation with diethylphosphoryl chloride to form the phosphate ester,the maximum absorption wavelength was red-shifted to the near infrared region and achieved colorimetric sensing.In chapter 4,a phosgene probe was designed and synthesized with amino cyanine as the probe matrix and terminal amino group as the site of action.In this chapter,we used of phosgene dual amidation reaction characteristics,through the formation of ureido,and the formation of new dimer,which the blue shift of absorption spectra,realized the sensing probe molecules on phosgene.The addition of phosgene maked the color of the system change from blue to red,indicating that the sensing system can be used for naked eye detection of phosgene.The probe reaction speed,detection sensitivity,and had a good selectivity. |
