Preparation Of Brush-Like Fluorescent Microspheres And Its Application In Ion Detection

In recent years,fluorescent microspheres have gradually become a research focus in the fields of biology and environmental detection.Compared with fluorescent substances,fluorescent microspheres with special functional groups have their own unique advantages,including stable morphology,narrow particle size distribution,monodispersity,and efficient luminous efficiency.These advantages have attracted widespread attention from domestic and foreign researchers on fluorescent microspheres.Although fluorescent microspheres have extremely important applications in many fields,especially in biomedicine and other fields,considering the further application of fluorescent microspheres,the development of fluorescent microspheres is far from enough.At present,most of the fluorescent microspheres used in China rely on imports.It is still a challenge to develop high-brightness fluorescent microspheres with a narrow particle size distribution and stable performance.Therefore,the preparation of high-luminance,stable and non-toxic fluorescent microspheres is still a challenge.It is of great significance to the development of China's biomedical testing and other fields,currently.The research contents of this article are as follows:Based on the photoemulsion polymerization method,different brush-like polymer microspheres were prepared using different monomers as raw materials.Different amounts of acrylic acid and 2-aminoethyl ester hydrochloride monomer were added to obtain brush-like polymer microspheres with different chain lengths.SEM results show that the brush polymer microspheres were uniformly distributed and relatively regular.The size of the brush-like polymer microspheres was measured with a laser particle size analyzer.It was found that the obtained brush-like polymer microspheres had a relatively narrow distribution,and its distribution coefficient PDI was within 0.2.The conductivity of the brush-like polymer microspheres was characterized by a conductivity meter,and the carboxyl group content could reach 9mmol/g.Brush-like fluorescent microspheres emitting green light were obtained by chemical coupling method.The fluorescent microspheres were prepared by adsorption-induced coupling method and traditional coupling method,respectively.It was found that the adsorption-induced coupling method could make full use of the ultra-high content carboxyl on the surface of brush-like polymer microspheres.Brush-like fluorescent microspheres were prepared using brush-like polymer microspheres with different particle sizes?144 nm?355 nm?as the matrix.By changing the carboxyl content of the brush polymer microspheres and the amount of5-aminofluorescein added,the fluorescence intensity of the brush fluorescent microspheres can be easily controlled.The factors influencing the preparation of brush-like fluorescent microspheres were investigated,including the effects of different buffers and the chain length of different brush-like polymer microspheres.For fluorescence intensity of the brush-like polymer microspheres,the influencing factors of p H,ultraviolet light and surfactants were discovered.brush-like fluorescent microspheres are sensitive to p H and are more stable under ultraviolet light.The presence of surfactants will sensitize the brush-like fluorescent microspheres.The prepared brush-like fluorescent microspheres can be used as selective and sensitive fluorescent probes for the determination of copper and sulfur ions.The quenching efficiency?F₀-F?/F₀ of brush-like fluorescent microspheres exhibits a good linear relationship with Cu?II?in the range of 0?0.5?M.The fluorescence intensity of the brush-like fluorescent microspheres with copper ions will increase after adding sulfur ions,and there is a good linear relationship between the fluorescence intensity and the concentration of sulfur ions in the range of 0 to 0.5?M.