Fluorescent silica nanoparticles (FSNPs), amino-modified fluorescent silica nanoparticles (NH2-FSNPs) and amino-modified fluorescent silica nanoparticles connecting with antibody have been synthesized in this paper. High-resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), Zeta potential, IR, fluorescent microscope and confocal fluorescent microscope were used to characterize these three types of nanoparticles. FSNPs are monodisperse in aqueous solution and NH2-FSNPs tend to aggregate since the modification could alter the surface Zeta potential and form hydrogen bonding between amino groups on the surface of FSNPs, but these particles could disperse well again when NH2-FSNPs connecting with antibodies further, the reason is the pH value of buffer solution was proper for NH2-FSNPs to disperse well in the liquid, and amino groups on particles surface have been involved in the connection with antibodies. The NH2-FSNPs showed good specificity and stability as they were used to recognize mesenchymall stem cells (MSCs) through CD44 on cell membrane. The fluorescent light emitted from NH2-FSNPs was strong and it was easy to observe the target cells by microscopy. The study in this work has provided excellent examples for NH2 modification, antibody connection and cell detection application by using FSNPs.%在微乳液体系中合成荧光二氧化硅纳米颗粒(FSNPs),然后对其表面进行氨基修饰,之后再连接抗体,应用高分辨透射电镜(HR-TEM),原子力显微镜(AFM),Zeta-电位分析仪,IR,荧光显微镜及激光共聚焦显微镜等多种表征工具对合成的颗粒和后续的修饰进行了系统分析.研究表明,FSNPs在溶液中呈现单分散状态,但是在表面修饰了氨基之后(NH2-FSNPs),由于表面平均电位以及氨基间氢键的形成,致使颗粒严重聚集;适当的pH环境可以改善颗粒的分散状态;利用氨基修饰的荧光二氧化硅纳米颗粒(NH2-FSNPs)连接抗体识别脐血来源的间充质干细胞(MSCs)表面的蛋白CD44,从而实现对间充质干细胞荧光成像分析.结果表明,识别效果良好,为荧光二氧化硅纳米颗粒在干细胞领域的应用奠定了基础.
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