Dr. B.P.S. Chauhan would like to gratefully acknowledge William Paterson University for assigned release time (ART) award for part of the research described here and also for the research program in general.

Note: All reagents are used as is from manufacturer with no further purification. Reactions were monitored for up to one week via UV-Vis spectroscopy to ensure complete reduction. All reactions are carried out under a vent hood and appropriate safety attire is worn at all times, including gloves, eye goggles, and lab coats.
1. Synthesis of Silver Nanoparticles
<ol>
	<li>Weigh out 0.0169 g (0.1 mmol) of silver nitrate directly into a 50 ml Erlenmeyer flask.</li>
	<li>Add in 20 ml of 18.2 M&#9...

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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+silver+nanoparticles+by+microbial+method+and+their+characterization.">Synthesis of silver nanoparticles by microbial method and their characterization.</a> Arch. Phys. Res. 2 (3), 153-158 (2011).</li><li>Ghosh, S., Sarma, N., Mandal, M., Kundu, S., Esumi, K., Pal, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+gold+nanoparticles+in+micelle+by+UV-irradiation:+A+conductometric+study.">Evolution of gold nanoparticles in micelle by UV-irradiation: A conductometric study.</a> Curr. Sci. 84 (6), 791-795 (2003).</li><li>Paul, B., Bhuyan, B., Purkayastha, D. D., Dey, M., Dhar, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Green+synthesis+of+gold+nanoparticles+using+Pogestemon+benghalensis+(B)+O.+Ktz+leaf+extract+and+studies+of+their+photocatalytic+activity+in+degradation+of+methylene.">Green synthesis of gold nanoparticles using Pogestemon benghalensis (B) O. Ktz leaf extract and studies of their photocatalytic activity in degradation of methylene.</a> Mater. Lett. 148, 37-40 (2015).</li><li>Chauhan, B. P. S., Rathore, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regioselective+Synthesis+of+Multifunctional+Hybrid+Polysiloxanes+Achieved+by+Pt-Nanocluster+Catalysis.">Regioselective Synthesis of Multifunctional Hybrid Polysiloxanes Achieved by Pt-Nanocluster Catalysis.</a> J. Am. Chem. Soc. 127, 5790-5791 (2005).</li><li>Chauhan, B. P. S., Rathore, S., Bandoo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#34;Polysiloxane-Pd&#34;+Nanocomposites+as+Recyclable+Chemoselective+Hydrogenation+Catalysts.">&#34;Polysiloxane-Pd&#34; Nanocomposites as Recyclable Chemoselective Hydrogenation Catalysts.</a> J. Am. Chem. Soc. 126, 8493-8500 (2004).</li><li>Chauhan, B. P. S., Rathore, S., Chauhan, M., Krawicz, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+Polysiloxane+Stabilized+Palladium+Colloids+and+Evidence+of+Their+Participation+in+Silaesterification+Reactions.">Synthesis of Polysiloxane Stabilized Palladium Colloids and Evidence of Their Participation in Silaesterification Reactions.</a> J. Am. Chem. Soc. 125, 2876-2877 (2003).</li><li>Chauhan, B. P. S., Sardar, R., Tewari, P., Sharma, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> , 23-25 (2003).</li><li>Pouchert, C. J., Pouchert, C. .. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-Aromatic+Amines.">Non-Aromatic Amines.</a> The Aldrich Library of Infrared Spectra. , (1983).</li><li>Arkles, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infrared+Analysis+of+Organosilicon+Compounds:+Spectra-Structure+Correlations.">Infrared Analysis of Organosilicon Compounds: Spectra-Structure Correlations.</a> Silicon Compounds Register and Review. , (1987).</li><li>Corriu, R. J. 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Salts reported in this paper are the only salts that were tested of that metal. As a result, it is uncertain that this reaction strategy would work with all salts of the metals, particularly gold. The solubility of these salts in water may also affect the outcome of the reaction in terms of reaction time, morphology, and yields. In all reactions, the silane was added to an already dissolved metal salt solution.
It is worth noting that care must be taken to ensure accuracy for these reactions r...

As the demand and applications of designer nanomaterials increases, so do the various methods of synthesis. The &#34;top-down&#34; methods, such as laser ablation or chemical etching have been employed for their excellent controllability and capability of resolving materials reliably down to the sub-micron level. These methods rely on bulk materials being processed into finer components, which typically increase the cost of production as the desired nanostructure size decreases. An alternative method of synthesis to this is the &#34;bottom-up&#34; approach, which controls synthesis at the molecular level and builds up to the desired nanostructure. This imparts a significant degree of control on the desired self-assembly, functionality, passivity, and stability in the generation of these nanostructured materials1. By working from the molecular level, hybrid nanocomposites can be generated providing the benefits of both materials within the same structure.
As nanomaterials are synthesized through the bottom-up strategy, methods need to be employed to control particle size, shape, texture, hydrophobicity, porosity, charge, and functionality2. In metal core nanoparticle synthesis, the initial metal salt is reduced in an autocatalytic process to generate zero-valent particles, which in turn direct the nucleation of other particle. This leads to clustering and finally nanoparticle production3. In an effort to control the size of nanoparticles created and prevent them from precipitating out of solution, stabilizers such as ligands, surfactants, ionic charge, and large polymers are exploited for their ability to block nanoparticles from further agglomeration4-10. These materials inhibit the van der Waals attraction of the nanoparticles, either through steric hindrance due to the presence of bulky groups or through Coulombic repulsions3.
In this work, a facile, one pot, synthetic strategy for the generation of various metal core nanoparticles using the silane, n-(2-aminoethyl)-3-aminosilanetriol (2-AST) is presented (Figure 1). Ligands on this compound are capable of reducing metal precursors and stabilizing metal nanoparticles with a relatively high efficacy. The three silanol moieties present are also capable of crosslinking and this forms an interconnected network of organosilane polymer impregnated with nanoparticles within its matrix (Figure 2). Unlike most silanes, which readily undergo hydrolysis in the presence of water, this compound is stabilized in water, which is beneficial for hydrophobicity purposes, stability, and control.

<table border="0" cellpadding="0" cellspacing="0" width="644">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">n-(2-aminoethyl)-3-aminosilanetriol (2-AST)</td>
			<td style="width:209px;">Gelest</td>
			<td style="width:72px;">SIA0590.0</td>
			<td style="width:76px;">25% in H2O</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Silver nitrate</td>
			<td>Sigma Aldrich</td>
			<td>S6506</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Gold(III) chloride trihydrate</td>
			<td>Sigma Aldrich</td>
			<td align="right">520918</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Palladium(II) Nitrate</td>
			<td>Alfa Aesar</td>
			<td align="right">11035</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Deuterium Dioxide</td>
			<td>Cambridge Isotope Laboratories</td>
			<td>DLM-4-100</td>
			<td></td>
		</tr>
	</tbody>
</table>

generation of zerovalent metal core nanoparticles using n-(2-aminoethyl)-3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of n-(2-aminoethyl)-3-aminosilanetriol is presented. This compound can be used to effectively reduce and complex metal salts into metal core nanoparticles coated with the compound. By controlling the concentrations of salt and silane one is able to control reaction rates, particle size, and nanoparticle coating. The effects of these changes were characterized through transmission electron microscopy (TEM), UV-Vis spectrometry (UV-Vis), Nuclear Magnetic Resonance spectroscopy (NMR) and Fourier Transform Infrared spectroscopy (FTIR). A unique aspect to this reaction is that usually silanes hydrolyze and cross-link in water; however, in this system the silane is water-soluble and stable. It is known that silicon and amino moieties can form complexes with metal salts. The silicon is known to extend its coordination sphere to form penta- or hexa-coordinated species. Furthermore, the silanol group can undergo hydrolysis to form a Si-O-Si silica network, thereby transforming the metal nanoparticles into a functionalized nanocomposites.

The reaction was monitored via UV-Vis spectrometry as nanoparticle formation should produce peaks characteristic for each individual metal nanoparticle. The final analysis of synthesized materials was accomplished through TEM and FTIR. The FTIR spectra was obtained from dried powder of samples. The particle size analysis can be accomplished by measuring nanoparticle diameter from images obtained via TEM and averaging results.
Co...

Watch this Scientific Journal Video about Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol at JoVE.com

Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

A novel method for metal core nanoparticle synthesis using a water stable silanol is described.

Generation of Zerovalent Metal Core Nanoparticles Using n-(2-aminoethyl)-3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of ...

The overall goal of this protocol is to produce water-soluble metal core nanoparticles. This general method uses a silicon-based surfactant as both a reducing and a stabilizing agent. This method helps answer key questions about control of self-assembly functionality, passivity, and the stability of nanostructured materials.The main advantage of this technique is that a water-soluble silicon compound can reduce metal precursors to metal nanoparticles and efficiently stabilize them. It uses green conditions to create silox and metal nanocomposites which have applications in therapeutics drug delivery and heterogeneous catalyses. The implications of this technique are far-reaching because the surfactant can cross-link to form organo-silene gels impregnated with metallic nanoparticles.This method can be applied to create hybrids of most noble metals and can provide mechanistic insights into the formation of nanoparticles. By controlling the concentrations of salt and silene it is possible to control the reaction rates, particle size, and nanoparticle coating. To start the procedure first weigh out 16.9 milligrams of silver nitrate into a 50 milliliter erlenmyer flask equipped with a magnetic stir bar.Add 20 milliliters of 18.2 megaohm ultra-pure water to the flask and stopper it. Place the flask in an oil bath on a hot plate at 60 degrees Celsius and stir the solution. Next slowly add 144 microliters of 2-AST to the flask, using a precision micropipette.Flush the pipette several times with the mixture to ensure that all of the 2-AST is transferred. Every half-hour remove 100 microliters of the mixture using a precision micropipette and place it into a plastic cuvette for UV-Vis spectroscopy analysis. To the plastic cuvettes containing the sample add one milliliter of ultra-pure water and mix the sample in each of the cuvettes thoroughly by repeat pipetting.Transfer the cuvette to a UV-Vis spectrophotometer and record the absorbance spectrum. Discard the sample in an appropriate container when finished. After six hours, remove the flask from the oil bath and transfer the nanoparticle mixture to a 20 milliliter scintillation vial for storage.To begin the sample preparation for electron microscopy place a 200 carbon mesh Formvar coated copper grid onto a clean piece of filter paper. Once the sample has cooled to room temperature cast drop approximately 60 microliters of the nanoparticle mixture directly onto the grid using a one milliliter plastic Pasteur pipette. Allow the grid to dry for 24 hours.Load the grid into a transmission electron microscope and record images using 10 microampere current and 100 kilovolt accelerating voltage. To prepare the NMR sample, first use a precision pipette to transfer 50 microliters of deuterium oxide into a clean NMR tube. Next, slowly pipette 400 microliters of the nanoparticle mixture into the same NMR tube.Cap the tube and shake the top of the tube to force the mixture to the bottom. Mix the sample by shaking and repeatedly inverting the NMR tube. Insert the sample tube into the NMR magnet and record the NMR spectrum.To prepare the FTIR sample first place two milliliters of the nanoparticle mixture into a one dram glass vial. Continue by placing the vial into a vacuum dessicator. Connect the dessicator stopcock to a vacuum pump.Open it and then evacuate the dessicator. Use caution when drying the sample in a vacuum dessicator as rapid reduction of pressure may cause samples to flash boil, expelling some of the material out of the container. Once the vial no longer contains visible liquid, remove it from the dessicator, and scrape out the remaining solid sample using a clean spatula.Finally, place the sample onto an FTIR spectrometer fitted with zinc selenide crystal diode laser and record the FTIR spectrum. The formation of silver nanoparticles was monitored by UV-Vis Spectrometry analysis. The silver nanoparticles have a characteristic peak at 414 nanometers that increases with reaction time.Transmission electron microscopy was used to confirm the presence of silver nanoparticles. Analysis of the images shows that the majority of the nanoparticles were in the 10 nanometer size range. Fourier transform infrared spectroscopy was used to verify the complexation of the nanoparticles with 2-AST.Absorption at around 1000 reciprocal centimeters shows the presence of silicon-oxygen-silicon linkages and peaks at 3000 to 2750 reciprocal centimeters and 1550 to 1650 reciprocal centimeters are attributed to the amino group. Analysis of the NMR spectrum of the nanoparticles shows the coordination to the 2-AST by the shift in and appearance of new peaks between 2.72 to 3.40 parts per million. Once mastered, the reaction process can be set up within an hour.While performing this procedure, it's important to ensure the purity of the water. All experiments were carried out in ultra-pure, 18.2 megaohm water. Following this procedure, scanning electron microscopy or x-ray powder diffraction can be used to further elucidate structural features, such as morphology, size and particle roughness of the hybrid nanocomposites.After watching this video, you should have a good understanding of how to generate and analyze the stabilized metal-core nanoparticles. This method produces large quantities of water-soluble metal nanohybrids which can be capped with ligands for drug delivery applications. Don't forget that working with silver nitrate and other reagents can be hazardous.The use of protective equipment such as gloves, goggles and lab coats is strongly advised while performing this procedure. Thanks for watching, good luck with your experiments.

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7.5K ビュー.  William Paterson University. The overall goal of this protocol is to produce water-soluble metal core nanoparticles. This general method uses a silicon-based surfactant as both a reducing and a stabilizing agent. This method helps answer key questions about control of self-assembly functionality, passivity, and the stability of nanostructured materials.The main advantage of this technique is that a water-soluble silicon compound can reduce metal precursors to metal nanoparticles and efficiently stabilize them. It ...