Study On Preparation, Spectra And Application Of Chemical-reaction Based Fluorescent Probes

Chemical-reaction based fluorescent probes have been greatly developed inrecent years. The irreversible chemical reactions occured between probes andanalytes lead to a higher selectivity and sensitivity. And the probes have beenwidely used in ions and small molecular detection, as well as in cell images.Hydrazine, bisulfite and zinc are important chemical raw materials, which playimportant roles in industries and human’s the life. However, the overintake ofthem will cause serious deseases. Hence, it is very necessary to develop asatisfied detection method. In the thesis, three fluorescent probes were preparedand used for detecting hydrazine, bisulfate and zinc in aquous solutions. Therecognition performances were recorded by fluorescence spectra and UV-visspectra. And the reaction mechanisms between the probes and analytes werediscussed by using nuclear magnetic titration, high resolution massspectrometry and high performance liquid chromatography (HPLC). The maincontents are as follow:The luminous mechanism of fluorescent probe, as well as the recognitionmechanism of the fluorescent probe was discussed in the first chapter. The latest research results of fluorescent probe of sulphite and hydrazine were summarized,and these probes were introduced according to the reaction principleA ratio fluorescent probe2-1based on1,8-naphthalene imide fluorophorewas introduced in the second chapter. The probe showed a high selectivity andsensitivity to hydrazine in the sensing environment. And color changes could beobserved under the sunlight and UV light, respectively. The reaction couldfinish within5min, and the detection limit was0.67ppb, which was lower thanthe U.S. Environmental Protection Agency regulation of10ppb standard. Thesensing mechanism was verified by mass spectrum and HPLC analysis. Inaddition, the probe was applied to detect hydrazine in cells.A ratio fluorescent probe3-1for bisulfite was illustrated in the thirdchapter. The bisulfite undergoes a1,4-addition reaction with probe3-1in PBSbuffer, resulting in the conjugate structure and spectral changes. Nuclearmagnetic titration and mass spectrum analysis showed the mechanism of thereaction. The reaction could accomplish in90s, which indicated that the probewas a rapid response probe. The detection limit was5.6×109mol/L. The probecould be used for detecting bisulfite in sugar samples.A fluorescence turn-on probe4-1contained a C=N bond was shown incharter four. The easy-to-prepared probe could complex with Zn2+selectively inan aqueous solution. The C=N bond isomerization was restricted when additionof Zn2+which could release the fluorescent of the probe, leading significantchanges of color and fluorescence color. The binding constant between the probe and Zn2+was1.9×104mol-1, and the detection limit was3.4×10-8mol/L.A summarization was concluded in the fifth chapter, and some suggestionswere stated for the future work.