Organosilica Nanoparticles

1 Oiganically Modified Silane Nanopartides (ORMOSIL Nanopartides) 

Single-source ORMOSIL nanopartides have been prepared with reverse microemulsion using OTES (3) (46) and vinyl triethoxysilane (VTES) (4) [47]. The as-prepared ORMOSIL nanopartides contain interior -octyl groups and surface vinyl 

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Figure 4.2 Schematic structure of thiol-organosilica nanoparticles.

Thiol-organosilica nanoparticles have also been produced using a two-step process of acid-catalyzed hydrolysis and condensation of MPMS, followed by base-catalyzed condensation this resulted in a rapid formation of emulsion droplets with a narrow size distribution [51]. 

Figure 4.4 TEM images of thiol-organosilica nanoparticles prepared from MPMS as a function of time and MPMS concentration. MPMS nanoparticles prepared under condition A (a), condition B (b) and condition C (c) were observed after incubation periods of 1 day (upper row) and 3 days (lower row). Scale bars lOOOnm (Reproduced with permission from Ref [50] 2008, American Chemical Society.).

In order to examine the surface modifications of other thiol-organosilica nanoparticles with proteins, the nanoparticle solutions were mixed with GFP/protein solutions and evaluated with fluorescence microscopy. The thiol-organosihca nanoparticles were shown to be well dispersed, with a distinct fluorescence (Figure 4.9), which indicated an effective modification with GFP and retention of dispersion this contrasted with the TEOS nanoparticles, which showed no clear fluorescence (Figure 4.9). 

Figure 4.10 Flow cytometry analysis of silica particles surface-modified with protein and DNA. Epoxy-organosilica nanoparticles (a, c) and MPMS particles (b, d) modified with GFP (a, b) or fluorescein-labeled oligonucleotide (c, d) were analyzed. Red lines and green lines indicated before and after reaction, respectively (Reproduced with permission from Ref [52] 2008, American Chemical Society.).

Figure 4.14 Fluorescence microscopy and electron microscopy of mouse peritoneal cells containing fluorescent epoxy-organosilica nanoparticles containing rhodamine B.

Wang, L, Estevez, M.C., O Donoghue, M. and Tan, W. (2008) Fluorophore-ffee luminescent organosilica nanoparticles. Langmuir, 24,1635-9. 

Figure 11.8 (a) A scheme for the preparation templated with 40 nm silica nanospheres, of monodispersed organosilica nanoparticles (Reproduced with permission from Ref. [49]. by templating with silica nanospheres, (b) TEM Copyright 2013, the Royal Society of and SEM (inset) images of the hollow particles Chemistry.)... 

Koike, N., Ikuno, T., Okubo, T., and Shimojima, A. (2013) Synthesis of monodisperse organosilica nanoparticles with hollow interiors and porous shells using silica nanospheres as templates. Chem. Commun., 49, 4998-5000. 

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