Synthesis Of Water-soluble Porphyin-containing Conjugated Polymers And Their Application In DNA Detection

Water-soluble cationic conjugated polymers (CCPs) both have traditional conjugatedpolymers optical and electronic functions, good water solubility of the polyelectrolyte, highfluorescence quantum yield and the molar absorption advantages. All these superiorities leadCCPs as the sensors in aqueous systems having greatly used. And it can be used for detectingnegatively charged of DNA.In this thesis, a series of water-soluble conjugated polymer (P1~P3) containingporphyrin, fluorene and phenylene moieties was successfully synthesized by Suzukicoupling reaction, and ultimately we selected P1as the research object to detect DNA. Westudied the energy transfer of the CCPs, the effect of excitation wavelength on fluorescencespectra, the effect of DNA on absorption and fluorescence spectra of P1, the emissionspectral changes of P1with increasing viscosity, the cell imaging and cytotoxicity of P1.The results show that P1have strong electrostatic interactions with DNA. The UV andfluorescence spectra have significant changes. This is the first report on fluorescenceenhancement of porphyrin-containing conjugated polyelectrolyte induced by DNA, allowingdesign of an effective fluorescence turn-on DNA probe,with a result of the fluorescenceintensity increasing about20times. In addition, P1could be utilized as a fluorescent probe forcellular imaging, where blue fluorescence was observed in the cytoplasm. The cytotoxicity ofP1was significantly low.In all, we synthesized novel water-soluble porphyrin fluorescenceconjugated polymers witch can effectively detect and identify DNA molecules and exhibitingfluorescence "turn on", it can be used as cell imaging and exhibit low toxicity, it’s possiblethat P1will have broad application prospects in the field of DNA testing.In addition,a novel coumarin Schiff base compound (L) was synthesized and evaluatedas a chemoselective Fe3+and Al3+sensor utilizing“turn-on”fluorescence enhancement.Therewere7-fold and4-fold fluorescence enhancement of L at λem, max=488nm upon the additionof1equiv. of Al3+and Fe3+, respectively. Other metal ions, such as K+, Li+, Na+, Cu+, Mg2+,Ca2+, Ba2+, Cu2+, Fe2+, Hg2+, Ni2+, Sb3+, Sn2+, Zn2+, Ce3+, Cr3+, Pr3+, Sm3+and Sn4+had nosuch significant effect on the fluorescence of L, whereas In3+and Ga3+induced slightlyfluorescence enhancement of L. In addition, rapid photoresponse through fluorescence “turn-on” signaling displayed L via intramolecular O-H···N=CH interaction inphotoisomerized product (L’) has been described, where showed130-fold and65-foldfluorescence enhancement at λem, max=488and516nm, respectively. The results indicated L’was less reactive or inert toward metal ions.