Preparation And Application Of Nanosensors Based On Silica Shell Fluorescent Nanoparticles

With the development of nanotechnology, nanoparticles have been significantly applied in the fields of material science, biochemistry and medicine. The chemical and biological nanosensors based on nanoparticles have become a new focus in the research of nanotechnology, because their advantages such as small volume, high resolution, short response time, few sample and so on. Aimed at the above advanced direction, this thesis was focused on the preparation of nanosensors and application of these nanosensors in the biomedicine, which were on the basis of silica shell fluorescent nanoparticles technology developed by our group. This thesis mainly includes following three works.1.Preparation of ratiometric pH nanosensors and its appication in intracellular pH detection of the anti-tumor drugs treated Hela cellsThe ratiometric pH nanosensors that contained a pH sensitive indicator fluorescein isothiocyanate (FITC) and a reference dye tris(2, 2′-bipyidyl) dichlororuthenium(II) hexahydrate (RuBpy) had been prepared with O/W microemulsion method. The ratiometric pH nanosensors had an average diameter of 50 nm, good photastability and could be well dispersed in aqueous solution. The linear response range of the ratiometric pH nanosensors to pH was between 4.4 and 7.4. The small size of the ratiometric pH nanosensors allowed it to be easily taken up by cells for noninvasive intracellular pH measurement, so the intracellular pH of different anti-tumor drugs treated Hela cells had been detected by combination with the advantages of the small size of the ratiometric pH nanosensors and the flow cytometry analysis method. The results demonstrated that the intracellular pH change was different when the Hela cells was treated with different anti-tumor drugs, some would caused intracellular acidification, some would caused ntracellular basification, and some would barely caused pH change. The single living Hela cells uptaken with the ratiometric pH nanosensor was also imaged with laser confocal microscope, which were treated with anti-tumor drugs. The results indicated that ratiometric pH nanosensors based on the silica shell fluorescent nanoparticles could be used to real- time monitor the intracellular pH change.2. Research of the relationship of intracellular acidification and apoptosis in Hela cells based on pH nanosensors...