Study On The Preparation And Applications Of Novel Functionalized Fluorescent Mesoporous Nanoparticles

Fluorescent mesoporous nanomaterials hold great potential in biomedical and optoelectronicfields, such as drug delivery, cell labeling and gene vectors, due to their high specific surface area,stable fluorescence characteristics as well as excellent dispersibility and biocompatibility. Atpresent, the researchers focus on the preparation of mesoporous silica nanoparticles containingfluorescent materials including dye molecules, fluorescent proteins, semiconductor quantum dots,conjugated polymers and metal complex, etc.Herein, the thesis includes two parts in the preparation and application of novel fluorescentmesoporous silica. In the first part, we employed the ion-exchange and high temperature liquidpolymerization method to in situ synthesize fluorescent conjugated polymer of PPV in pores ofmesoporous silica nanoparticles （MSNs）. The influence of different ratios of double-sulfoniumsalt precursor and MSNs on optical properties of conjugated polymer functionalized MSNs（PPV@MSN） was studied. Additionally, by controlling the hydrolysis and condensation processof silica precursor in sol-gel, we designed and synthesized the core-shell fluorescent MSNscontaining PPV （PPV@MSN@nSiO₂@mSiO₂）, and investigated their applications in drugdelivery and cell labeling. The research results revealed that the synthesized fluorescent MSNswith different contents of PPV exhibited different luminescence intensities and colors. ThePPV-1@MSN sample with a ratio of1:1for PPV precursor to MSNs exhibited the superiorfluorescence characteristic and its Quantum Yield could reach71%. Furthermore, in the drugslow-releasing test based on IBU model, all products showed excellent drug release characteristics.In the second part, we successfully introduced the fluorescent complexes into the mercaptofunctionalized MSNs to prepare blue light MSNs through coordination effect betweenbenzothiazole and zinc ion. After that, RhB dye molecules were also adsorbed into theas-synthesized blue light MSNs via simple physical absorption. A series of hybrid nanoparticleswith different fluorescence emissions were obtained by adjusting the ratio of RhB dyes to thecomplex of benzothiazole and zinc. At the same time, we also successfully prepared white lightmesoporous silica nanomaterials （RhB-（BTZ）xZn@MSN）. In conclusion, these preparedfluorescent nanomaterials have a potential application feature in many field of biomedical drugdelivery, cell labeling and optoelectronic devices.