Synthesis Of Fluorescent Probe With Aggregation-induced Emission Feature And Its Application In Fluorescent Detection

Many studies reveal that Zn²⁺is involved in a number of biological processes.Therefore,real-time and accurate detection of Zn²⁺content is of great important for understanding these processes involving Zn²⁺.His-tag refers to an amino acid motif consisting of 6-10 histid ines fused to the end of the recombinant protein.His-tag is a representative epitope tag,which has been used widely in the purification or immobilization of recombinant proteins.It is of great significance for facilitating detection and analysis of proteins to design a fluorescent probe that is capable of rapidly and accurately detecting His-tagged proteins.The fluorescence probe based on the aggregation induced emission（AIE）feature is advantageous owing to its high detection sensitivity,low background fluorescence interference,and good photostability.Two AIE-active fluorescent probes were designed and synthesized for the detection of Zn²⁺and His-tagged proteins respectively.The main content and results of the thesis are as follows:Firstly,a red fluorescent probe with AIE characterstics（CTPE-IDA）for Zn²⁺was synthesized.CTPE-IDA displays good water solubility,excel ent photostability,large stokes shift,high selectivity toward Zn²⁺,fast response time and high detection sensitivity.After incubation with Zn²⁺,obvious size increase can be observed for CTPE-IDA aggregates,which clearly demonstrate that the FL change of CTPE-IDA upon Zn²⁺is due to the self-aggrega t io n of CTPE-IDA molecules after the formation of CTPE-IDA-Zn²⁺complex system.Secondly,CTPE-IDA was complexed with nickel ion(Ni²⁺)to obtain the fluorescent probe for His-tag(CTPE-IDA-Ni²⁺).The probe can detect His-tag in buffer solution.In addition,it can also be used in fluorescent labeling applications.It had the advantages of simple operation,low cost,low background interference and high detection sensitivity compared with the conventional Western blot analysis.After incubation with His-tagged protein,negligible size change could be observed for CTPE-IDA-Ni²⁺,indicating no aggregation happened,which clearly demonstrate that the FL change of CTPE-IDA-Ni²⁺upon His-tag labeling is the result of inhibition of intramolecular movements of the phenyl groups.CTPE-IDA-Ni²⁺exhibits the advantages of good water solubility,excel ent photostability,large stokes shift,fast response time,high detection sensitivity and high selectivity toward His-tag.