Preparation And Fluorescent Sensing Property Of Conjugated Polymer Nanoparticles

In the past ten years,the conjugated polymer nanoparticles because of excellent optical properties had been successful applied to the various fields,including the sensing of pH,metal ions and temperature,imaging of tissues and disease biomarkers,photothermal ablation of tumors,real-time activation of neurons,as well as photodynamic therapy of cancers and microorganisms.These characteristics,Including the excellent optical properties,good light resistance,surface functionalization modified easily,good biocompatibility,also make the application of conjugated polymer nanoparticles in biology has a great potential.In recent years,there have been many studies on the design of a series of new conjugated polymers,surface chemical modification and nanoengineering strategies,and then fluorescence imaging experiments in live animals was achieved.Future efforts should further expand the biological study of conjugated polymer nanoparticles and may even be beyond the scope of pre-clinical research.A series of conjugated polymers with flexible side chains are synthesized in detail.And the nanoparticles with good dispersion and uniform size were successfully prepared by the conjugate polymer.Then the potential applications of nanoparticles to iron ion recognition are further studied.The main contents of this paper are as follows:?1?Five conjugated polymers with flexible side chains were synthesized by monomer hydroquinone and carbazole,and the molecular structure was confirmed by means of ¹HNMR,GPC and IR.?2?Nanoparticles with good morphology and functionalized nanoparticles were successfully prepared by using the four conjugated polymers.And the morphology and size of nanoparticles were confirmed and analyzed by means of Atomic Force Microscope,Transmission Electron Microscope,Scanning Electron Microscope and Dynamic Light Scattering.?3?The ultraviolet absorption spectra and fluorescence emission spectra of four conjugated polymers and conjugated polymer nanoparticles were measured and analyzed.The results showed that the ultraviolet absorption and fluorescence emission of conjugated polymers in organic and inorganic solvents were redshifted with the increase of the side chains of conjugated polymers.And the ultraviolet absorption and fluorescence emission of nanoparticles in organic and inorganic solvents also redshift with the increase of the side chains of conjugated polymers.The ultraviolet absorption spectra and fluorescence emission spectra of four conjugated polymer nanoparticles to the selectivity of metal ions were measured and analyzed.The results showed that the four nanoparticles have obvious interaction with Fe³⁺and showed a good recognition effect on Fe³⁺.In addition,it is inferred that Fe³⁺is the result of the changes of ultraviolet absorption spectra and fluorescence emission spectra caused by the aggregation of nanoparticles.The fluorescence emission spectra of four conjugated polymer nanoparticles in the sensitivity of Fe³⁺were measured and analyzed.And the results showed that the four conjugated polymer nanoparticles not noly have good sensitivity to Fe³⁺but also the sensitivity was high.The nanoparticles reacted rapidly in the Fe³⁺in the very low concentration of 0.2?mol/L.?4?The sensitivity of the four CPNs to acid and alkali was tested,and the ultraviolet absorption spectra and fluorescence emission spectra of four CPNs in the different value of pH environments were determined and analyzed.The ultraviolet absorption spectrum the four CPNs occurred the redshift when the pH=14,and the fluorescence intensity of the four CPNs were quenched in acid environment,and with the increase of the acid,the four CPNs fluorescence intensity has showed the trend of weakeness.