Development Of Novel Fluorescence Probes For Cu(Ⅱ) And Thiophenol And Their Applications In Environmental Analysis

The disharmonious relationship between humans and the natural environment makes environmental problems more and more serious and a growing number of environmental pollutants arose, diffused, accumulated in humans and plants. In recent years, environmental pollutants, including heavy metals, transition metal ions, organic /inorganic small molecules (i.e. thiophenol), are attracted more and more attention because of their harmfulness. Traditional detection techniques including various spectroscopy, chromatography, mass spectrometry have been applied for environmental analysis, however, these instruments need complex sample pretreatment process, skilled operator, long time analysis or large consumption of organic reagent and so on. In recent years, because of the advantage of fluorescence probe, the use of fluorescence detection based on small molecules has a rapid development in many field include, such as cell imaging, environmental monitoring, immunoassay and environmental protection. Fluorescent probes are rationally designed, synthesized and applied to environmental analysis of metal ions, cations and toxic inorganic/organic small molecules. Compared with quenched probe, amplified fluorescence probe can effectively avoid interference in organism and get more accurate results. Among many excellent fluorophores, coumarin and rhodamine have become more and more widely used in construction of probes which can be used in environmental analysis because of its good light stability and ease of modification.In this paper,8-hydroxyjulolidine is used as a starting material for development of novel fluorescent probes based on rhodamine 101 derivatives and coumarin derivatives for Cu2+, thiophenol detection, respectively.In the second chapter, a new synthesized method of 8-hydroxyjulolidine was firstly proposed. Then, rhodamine 101 derivative (R101P) and coumarin derivative (Cou-ArSH) were designed, synthesized and characterized, respectively.In the third chapter, R101P was successfully employed for Cu2+detection in real samples and living cells via ring-opening processes of rhodmamine spirolactam mechanism. In the test system, solution of probe is colorless, however, the color of the solution changes to pink and the fluorescence intensity of solution enhances significantly in the presence of Cu2+. Fluorescence spectra shows that the probe exhibits a good linearity to Cu2+ when it ranges from 4×10-6 to 1.6×10-5 M and the detection limit can reach 40 nM. Finally, the probe was applied for the detection of Cu2+in real samples and living cells with satisfactory results.In the fourth chapter, probe (Cou-ArSH) was designed, synthesized for the detection of thiophenol in real water samples and living cells. Aminocoumarin was chosen as fluorophore due to its high fluorescence quantum yield and easy modification and 2,4-dinitrobenzene sulfonamide group was chosen as recognition unit because it can quench fluorescence of aminocoumarin and be eliminated by thiophenol. In the absence of thiophenol, the solution shows none fluorescence. Upon addition of thiophenol, a significant fluorescence enhancement occurred accompanied by dramatic color changes from red to bright green. When adding an equal equivalent amount of thiophenol, the fluorescence intensity can increase 47 fold. Cou-ArSH shows a good linearity with thiophenol when it ranges from 10-6 M to 10-5 M and the detection limit can reach 4.6×10-7 M. Finally, the probe is successfully used in water samples and living cells for thiophenol detection.