Detection Of Bioactive Molecules By Functionalized Small Molecule Fluorescent Probe And Its Application In Biochemical Analysis

Cancer is still a great challenge to human health at present.As it is difficult to diagnosis cancer in its early stage,simple and rapid means of early diagnosis of cancer need to be put forward.Enzymes play important roles in many physiological,pathological and pharmacological processes.The abnormal activity of enzymes is closely related to cancer.The sensitive and visual detection of cancer-related enzymes is very important for the early diagnosis and prognosis of cancer.The sensitive and visual detection of cancer-related enzymes is very important for the early diagnosis and prognosis of cancer.Small molecular fluorescent probes are suitable for the highly selective quantitative determination of enzymes due to their high sensitivity,simple,non-invasive rapid analysis and real-time detection performance.In this thesis,two longwavelength "lighting-on" fluorescent probes were proposed for the determination of cancer-related biological enzymes.The specific research contents are as follows:1.γ-glutamyltransferase(GGT),an important tumor marker,is highly expressed in tumor tissues,and precise detection of its activity provides a vital indicator for the diagnosis and treatment.In this work,a “lighting-on” probe(TCF-GGT)was elaborated to detect endogenous GGT with high selectivity and sensitivity.Dicyanomethyldifuranyl(TCF-OH)was employed as the fluorescence reporter and short peptide glutathione(GSH)worked as the GGT-active trigger,the introduction of which prevented the initial proton transfer of TCF-OH contributing to a blank sensing background.A bright red fluorescence could be switched on upon GGT catalytic hydrolysis,avoiding the potential interference from background.There displayed an excellent water-solubility,and little organic solvent was required during the exploration,which otherwise avoided the potential damage to enzyme and organism.TCF-GGT has been proved to be workable at cellular and organism level with highly effective imaging and a short metabolic cycle,which is expected to offer an alternative solution or reference to the early diagnosis and treatment of tumor.2.The upregulation of nitroreductase(NTR)expression has been widely used to evaluate the anoxic microenvironment of solid tumors.Here,we propose a near infrared(NIR)fluorescent probe Q-NTR waken up by nitro reductase(NTR)in mitochondria.The presence of strong electron-absorbing group nitro can quench fluorescence and reduce background signal.Q-NTR is activated by nitroreductase in the presence of the coenzyme NADH,producing significant NIR fluorescence.The probe can detect the activity of nitro reductase to evaluate the degree of hypoxia in tumor tissues.Due to its properties of near infrared emission,subcellular structure level imaging,rapid response,etc.,it has been successfully applied to monitor endogenous NTR activity in subcellular structure in anoxic microenvironment,and can selectively stain cells under anoxic condition.In addition,the combination of mitochondrial localization function and NTR detection function lays a foundation for further study of cellular metabolic pathways under hypoxia conditions...