The Preparation Of Water-Soluble Conjugated Polymers And Their Applications In Biological Sensing

In recent years, water-soluble conjugated polymers have attracted considerable attention because of their wide application in chemistry, medicine and biological sciences. As a new class of water-soluble fluorescent molecules, water-soluble fluorescent conjugated polymers have a lot of advantages, for example, high absorption coefficients, high fluorescence quantum yields, excellent solubility and so on.Therefore, Water-soluble fluorescent conjugated polymers can be widely applied in biochemical analysis. The purpose of this paper is to develop high sensitive method of biological detection based on water-soluble fluorescent conjugated polymers, which comprises the following contents:(1) The synthesis of water-soluble cationic fluorescent conjugated polymersA neutral poly(p-phenyleneethynylene) derivative(PFEP) was synthesizd through Sonogashira coupling reaction, water-soluble cationic conjugated polymer(PFEPN+) was achieved from neutral polymer by quarter of amination reaction. Because side chains of the water-soluble cationic conjugated polymer(PFEPN+) contained a number of amine groups, the cationic conjugated polymer has excellent water-solubility. The structure of polymer was confirmed by 1H NMR spectrum as well as Gel Permeation Chromatography(GPC), and the photo-physical properties were characterized by UV-Vis absorption and photoluminescence(PL) spectra.(2) Detection of DNA based on cationic conjugated polymer and hybridization chain reaction.A novel homogeneous HCR assay is developed by using cationic conjugated polymer(PFEPN+) as indicator for detection of DNA. After the HCR, the two hairpin probes are triggered by target DNA to form a long two-stranded DNA polymer with numerous fluorescein labeling in the strand. When the PFEPN+ are added, effective fluorescence resonance energy transfer(FRET) from the PFEPN+ to the fluorescein-labeled DNA occurred, which can generate a substantially apparent increase in the corresponding fluorescein emission intensity. This proposed cascade amplification strategy can not only extends the application of HCR but also provides an alternative platform for homogeneous detection of DNA.(3) Detection of cancer cells based on cationic fluorescent conjugated polymer and Mucin 1 aptamer probeA novel amplified platform for the selective and quantitative detection of cancer cells was developed based on cationic fluorescent conjugated polymer as reporter, fluorescein modified DNAb probe as the receptor and MCF-7 as target cancer cells.