Synthesis And Performance Study Of Water-soluble Two-photon Fluorescent Probe Based On Spirobifluorene Framework

With the development of science and technology,more and more researchers have paid attention to fluorescent probes,which have been widely used in the fields of cytobiology,analytical chemistry and biochemistry.The long-wave absorption of the two-photon fluorescent probe reduces the damage of the medium,and the imaging penetration is strong to realize the deep tissue imaging of the organism.The spirobifluorene structure can effectively avoid?-?stacking,reduce the generation of excimer,and can also effectively reduce the luminescence intensity of the material,and the structure can be easily modified to realize the functionalization of the material.Although the two-photon fluorescent probes derived from spirobifluorene have excellent performance,the poor water solubility of such fluorescent probes limits its detection in cell biological tissues.Therefore,this paper aims to improve the water solubility of such fluorescent probesThe work of this paper is divided into the following sections:Part I:Design and synthesis of eight spirobifluorene-based compounds SPF-A3,SPF-A4,SPF-B3,SPF-B4,SPF-C2,SPF-C3,SPF-D2,SPF-D3,and Its structure was characterized.Part II:The related properties of SPF-A4 were studied.The water solubility of SPF-A4 was improved and it can be applied to the whole water system.It was found to be a high sensitivity and high selectivity of two-photon fluorescence of Hg²⁺.The fluorescence intensity of SPF-A4 is linear with Hg²⁺concentration within a certain concentration range.The linear fitting equation is Y=-1.4x10⁴[Hg²⁺]+0.769,which can quantitatively detect Hg²⁺within a certain range,the detection limit is 182nM;Part?:The related properties of SPF-B4 were studied,its water solubility was improved,it can be applied to the whole water system.It was found to be a high sensitivity and high selectivity of two-photon fluorescence of Ag⁺.The fluorescence intensity of SPF-B4 is linear with Ag⁺concentration within a certain concentration range.The linear fitting equation is Y=-8.67x10⁴[Ag⁺]+0.896,which can quantitatively detect Ag⁺within a certain range,the detection limit is 64nM;Part?:The properties of SPF-C3 and SPF-D3 were studied.It was found that both probes are pH water-soluble two-photon fluorescent probes,which can be applied to the whole water system.SPF-C3 can be detected in the range of pH 2.3-6.3,and SPF-D3 can be detected in the range of pH 1.8-5.2.Part?:The properties of SPF-C2 and SPF-D2 were studied,and found that these two probes are fluorescent probes for detecting the water content in organic solvents.Their detection limits for water content in 1,4-dioxane are respectively 0.00136%,0.00978%,which were an order of magnitude lower than the general literature report,the detection limits of water content in THF are 0.00283%and 0.0297%,respectively,and the two compounds have the better performance in detecting water content in 1,4-dioxane.