Editing Silica Nanoparticles (section)

=== Protocol 2  ===

Amino-modified silica nanoparticles were prepared using the synchronous hydrolysis of tetraethoxysilane and N-(beta-amimoethyl)-gamma-aminopropyltyiethoxysilane in water-in-oil microemulsion. First, a stable and transparent microemulsion was prepared by using the method as previously reported. A solution containing cyclohexane, TritonX-100, n-hexanol (with the ratio of volume: 4&nbsp;: 1&nbsp;: 1) was mixed, followed by the addition of adequate water and was stirred for 5 min. Then well-distributed mixture of tetraethoxysilane and N -(beta-amimoethy l)-gamma-aminopropyltyiethoxysilane (with the ratio of volume: 1&nbsp;: 1) was added to the microemulsion. With the initiation of ammonia, tetraethoxysilane and N-(beta-amimoethyl)-gamma-aminopropyltyiethoxysilane were synchronously hydrolyzed in the microemulsion to produce amino-modified silica nanoparticles. The whole reaction lasted for 24 h. Pure silica nanoparticles were prepared simultaneously by the controlled hydrolysis of tetraethoxysilane in microemulsion with the initiation of ammonia. At the same time, fluorescent nanoparticles have been prepared for studying the biocompatibility of the silica nanoparticles with cells, employing a highly luminescent dye complex of ruthenium ion and bipyridyl,<br>Tris(2,2 '-bipyridyl) dichlororuthenium (II) hexahydrate as the core of the nanoparticles silica nanoparticles could be easily prepared by using the hydrolysis of tetraethoxysilane in the<br>water-in-oil microemulsion without rigorous experimental conditions, such as high temperature, high pressure, etc. The size of the nanoparticles can be controlled through<br>varying the molar ratio of water to surfactant (R w ) and the molar ratio of TEOS to the ammonia (R N 19 ,20 J• 

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amino-modified silica nanoparticles are directly produced by the synchronous hydrolysis of tetraethoxysilane and N-(beta-amimoethyl)-gamma-aminopropyltri-ethoxysilane in<br>water-in-oil microemulsion with the initiation of ammonia. Nanoparticles produced by this method are uniform in size and well dispersed. There is no need to further<br>modify with aminosilanes, which provide a new, simple and safe method for the application of nanoparticles in the nanoparticles in the biomedicine research.<br>age of the amino-modified nanoparticles nanoparticles are (50 ± 4) urn in size I mg nanoparticles can bind 97.2 flg plasmid DNA<br> 

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