Fluorescent Nanoprobes Based On Polymers For Biological Detection

In recent years,conjugated polymer nanoparticles have attracted much attention because of their advantages of high fluorescence quantum yield,small particle size,high fluorescence brightness,excellent photostability and lower toxicity.Based on these unique fluorescence properties,conjugated polymers nanoparticles have very broad application prospects in biochemical analysis.Besides the extensive applications in cellular imaging and immunofluorescent labeling,CPNs have demonstrated utility in a wide range of applications such as intracellular pH value,temperature sensing and metal ion detection.The purpose of the anthors is to design and produce fluorescent probe based on conjugated polymer for the detection of pH,hyperchlorite in aqueous solution and cell imaging.The main research work includes the following aspects:Conjugated polymer(PFV and PFVMO)was synthesized by Wittig-Horner reaction.The structure of the compound was confirmed using 1H NMR,GPC,Maldi-tof etc.The photophysical properties of polymers were characterized by UV absorption spectra and fluorescence emission spectra.Furthermore,PFV/PSMA nanoparticles were prepared by coprecipitation method.The morphology and fluorescent properties of PFV/PSMA nanoparticles were characterized using DLS,TEM,UV and PL.The obtained PFV/PSMA fluorescent nanoparticles can be directly modified dopamine through amide condensation reaction,so as to construct a conjugated polymer fluorescent sensing probe.The conjugated polymer fluorescent sensing probe can realize pH detection,and has good reversible cyclic response to pH.Furthermore,it could be used in the detection of intracellular pH by confocal imaging and show good biocompatibility.Polyphenylene vinylene derivatives containing carboxyl chain(PPV-COOH)was synthesized by Gilch coupling reaction.The structure of the compound was confirmed using 1H NMR,GPC,Maldi-tof etc.The photophysical properties of polymers were characterized by UV absorption spectra and fluorescence emission spectra.The PPV-COOH nanoparticles were prepared by the precipitation method.The morphology and fluorescence properties of the conjugated polymer nanoparticles were characterized by DLS,TEM,UV and PL.The obtained PPV-COOH nanoparticles have optical stability and good optical properties.We realize the visualization of detection of hypochlorit by optimizing the experimental conditions,while accompanied by the phenomenon of fluorescence spectrum displacement.Furthermore,Infrared spectroscopy and GPC were used to investigate the detection mechanism.