Synthesis Of Lanthanide Doped Fluorescent Silica Nanoparticles And Its Application In Bacterial Field

Fluorescent silica nanoparticles(FSNPs)have shown great promise for applications in numerous fields,such as biomedical and chemical sensors.Among different routes for integrating fluorescence into the nanoparticles,doping lanthanides is attractive as it could successfully combine the advantages of lanthanides luminescence and silica nanoparticles together.The thesis consists of two parts:In the first part,we chelated lanthanide ions with a chromophore-ligand-silane conjugation,and then condensed the complex together with tetraethyl orthosilicate(TEOS)in reverse microemulsions,forming lanthanides-doped silica nanoparticles.This approach,on one hand,ensured the capability of adjusting the size and improved the doping capacity,and on the other hand made it possible to control excitation and emission wavelength as well as the fluorescent intensity.By using different chromophores and lanthanide ions,the energy transfer process in the lanthanides-doped nanoparticles was illustrated,and our work therefore might suggest a novel approach for engineering the energy levels for tuning fluorescence of silica nanoparticles.In the second part,in order to solve the bacterial infection problem,we made the vancomycin molecules covalently coupled with the lanthanide chelate and then condensed the complex together with TEOS in reverse microemulsions,forming the vancomycin and lanthanides co-doped silica nanoparticles(Van-FSNPs).At the end,we explored the interaction between Van-FSNPs and bacteria,and realized the binding and inhibition of Gram-positive bacteria with high speed,specificity and efficiency.