Redispersible Dried Powder Nanoparticles: Gold
- Pricing
- PVP
- 1 mg: $200
- 2 mg: $350
- 5 mg: $750
- Organic
- 1 mg: $50
- 5 mg: $150
- 50 mg: $500
Available Sizes PVP
- 5 nm
- 7 nm
- 10 nm
- 12 nm
- 15 nm
- 17 nm
- 20 nm
- 30 nm
- 40 nm
- 50 nm
- 60 nm
- 70 nm
- 80 nm
- 90 nm
- 100 nm
- Econix
- Other sizes available upon request
Available Sizes Organic
NanoComposix's dried gold nanopowders are formulated with polymer or alkanethiol surface coatings which allow the nanoparticles to easily be redispersed as unagglomerated dispersions in a variety of solvents. We have verified the redispersion with transmission electron microscopy (TEM), UV-visible spectroscopy and dynamic light scattering.
PVP Stabilized Gold Nanopowders:
- Unagglomerated after dispersion into water, DMF, acetonitrile, methanol and many other solvents
- Polyvinylpyrrolidone (PVP) surface coating (0.1 - 0.5% PVP as excipient)
- Sizes ranging from 5-100 nm with narrow distributions, CV's < 15%
Organic Dispersible Gold Nanopowders:
- Unagglomerated after dispersion into hexane, toluene, chloroform and many other organic solvents
- Dodecanethiol capping agent
- Available with a size of 2 nm, 4 nm, and 5 nm with CV's < 20%.
Storage and Handling Documents
Table of Contents:
- Dispersion Properties of PVP Stabilized Gold
- Solvent Compatibility of PVP Stabilized Gold
- Dipsersion Properties of Dodecanethiol Stabilized Gold
- Solvent Compatibility of Dodecanethiol Stabilized Gold
Dispersion Properties of PVP Stabilized Gold
Gold nanoparticles are plasmonic nanoparticles that have a color that is a function of the size, shape, and agglomeration state. Most commercially available dried gold nanoparticles are grey in color both as a powder and when redispersed in water. At nanoComposix, we have developed methods to allow for dried gold nanoparticles to be redispersed in an unagglomerated format. The resdipsersion is verified by measuring the optical spectrum of the gold nanoparticles before and after drying. The following images and graphs show the redispersion properties of PVP stabilized gold nanoparticles.
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The gold nanoparticles are redipsersed by adding a miscible liquid to the lyopholized gold nanoparticles and then bath sonicating for 30 seconds. After reconstitution, the particles should be stored in the dark in a fridge in a sealed container. Different sized gold nanoparticles have different amounts of polyvinylpyrollidone added to the gold nanoparticles to stabilize the particles against agglomeration. The following table shows the polyvinylpyrollidone added for each gold nanoparticle size:
| Nanoparticle Size (nm) | Ratio of PVP:Au by Mass | PVP in 1 mg/mL Au Solution (w/w) |
|---|---|---|
| 5 | 1:1 | 0.1% |
| 7 | 1:1 | 0.1% |
| 12 | 1:1 | 0.1% |
| 15 | 1:1 | 0.1% |
| 17 | 3:1 | 0.3% |
| 20 | 3:1 | 0.3% |
| 30 | 5:1 | 0.5% |
40 | 3:1 | 0.3% |
| 50 | 3:1 | 0.3% |
| 60 | 5:1 | 0.5% |
| 70 | 3:1 | 0.3% |
| 80 | 3:1 | 0.3% |
| 90 | 5:1 | 0.5% |
| 100 | 5:1 | 0.5% |
Solvent Compatibility of PVP Stabilized Gold
The dried gold nanoparticles can be redispersed in a variety of polar solvents. The table below shows solvents that the gold nanoparticles are soluble in. This knowledge base article shows the effect on the optical properties of gold into various solvents. Optical shifts in the gold spectrum can be predicted using the index of refraction and nanoComposix's Mie Calculator.
| Solvent | Solvent Refractive Index, n | Nanopowder Solubility |
|---|---|---|
| Water | 1.34 | High |
| Methanol | 1.33 | High |
| Ethanol | 1.36 | High |
| Isopropanol | 1.38 | High |
| DMF | 1.43 | High |
| DMSO | 1.48 | High |
| Chloroform | 1.45 | Medium |
| Acetonitrile | 1.34 | Low |
| THF | 1.41 | Low |
| Dichloromethane | 1.42 | Low |
| Hexane | 1.38 | None |
| Toluene | 1.50 | None |
Dispersion Properties of Dodecanethiol Stabilized Gold
Alkanethiol capped gold nanoparticles can be dried down by gently warming and evaporating the solvent. The following spectrum shows that there is very low agglomeration associated with the redispersed nanoparticles.
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Solvent Compatibility of Dodecanethiol Stabilized Gold
Dried dodecanethiol functionalized gold nanoparticles are redispersible in a variety of different polar organic solvents. To redisperse organically functionalized gold nanoparticles, add the appropriate solvent to the vial and shake or bath sonicate for 30 seconds. Once prepared, the gold nanoparticles should be stored in the dark in the fridge in a sealed container. Small differences in the spectra will be observed depending on which solvent the gold nanoparticles are redispersed in. See our knowledge base article on organic solvent compatibility for more details on this effect.
| Solvent | Solvent Refractive Index, n | Nanopowder Solubility |
|---|---|---|
| Toluene | 1.50 | High |
| Chloroform | 1.45 | High |
| Dichloromethane | 1.42 | High |
| Hexane | 1.38 | High |
| THF | 1.41 | High |
| DMF | 1.43 | None |
| DMSO | 1.48 | None |
| Acetonitrile | 1.34 | None |
| Isopropanol | 1.38 | None |
| Ethanol | 1.36 | None |
| Methanol | 1.33 | None |
| Water | 1.34 | None |