4 nm Dodecanethiol-Stabilized Gold Nanospheres

Product Number

$95.00

  • Unagglomerated and monodisperse
  • Dodecanethiol functionalized surface
  • Mean diameter: 4.0 nm ± 1.0 nm
  • Size distribution (CV) < 20%
  • Available dried and can be reconstituted in your solvent of choice

Product Lines

Tight Size
Distribution
Wide Variety
of Surfaces
Available
Dried
Guaranteed Sterile
& Endotoxin-Free
Highly
Concentrated
Lower
Cost
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(certain products)

(certain products)
  • Monodisperse and unagglomerated
  • Standard colloidal concentration
  • Seven standard surfaces (citrate, tannic, PVP, lipoic acid, PEG, BPEI, silica)

Which Surface Should I Choose?

Surface Displaceable Salt
Stability
Stable in
Water
Stable in
Alcohols
Stable in
Polar Organics
Stable in
Non-Polar Organics
Conjugatable Charge
at pH 7
Dodecanethiol Learn more + N/A
  • Hydrophobic coating renders particles soluble in organic solvents and compatible with non-polar polymer composite materials
  • Can be dispersed in low surface-energy solvents for coating applications requiring uniform particle deposition

Certificate of Analysis Examples

Please note that these are representative Certificates of Analyses (CoAs) provided as examples for this product. We provide a unique batch-specific CoA with each product during shipment; only the CoA that arrives with your product should be referred to for actual characterization and measurement data. If you would like an electronic copy of the CoA for the product you received or the material(s) we currently have in stock, please contact us.

Product Line Surface Example Certificate of Analysis Product # Price
D NanoXact, Dried Dodecanethiol Download ↓ AUDD4-1MG $95+
D NanoXact, Dried Dodecanethiol Download ↓ AUDD4-5MG $375+
D NanoXact, Dried Dodecanethiol Download ↓ AUDD4-25MG $1,095+
D NanoXact, Dried Dodecanethiol Download ↓ AUDD4-50MG $1,750+

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Gold Nanoparticle Applications

Diagnostic Applications

Gold nanopaticles are readily conjugated to antibodies and other proteins due to the affinity of sulfhydyl (-SH) groups for the gold surface, and gold-biomolecule conjugates have been widely incorporated into diagnostic applications, where their bright red color is used in home and point-of-care tests such as lateral flow assays.  

Biomedical Applications

Gold nanomaterials can be conjugated to biomolecules to specifically target cancer cells, and used for photothermal cancer therapy, where their tunable optical properties cause them to convert laser light into heat and selectively kill cancerous cells.   

Plasmonics

Gold nanoparticles have unique optical properties because they support surface plasmons. At specific wavelengths of light the surface plasmons are driven into resonance and strongly absorb or scatter incident light. This effect is so strong that it allows for individual nanoparticles as small as 30 nm in diameter to be imaged using a conventional dark field microscope.  This strong coupling of metal nanostructures with light is the basis for the new field of plasmonics.  Applications of plasmonic gold nanoparticles include biomedical labels, sensors, and detectors. The gold plasmon resonance is also the basis for enhanced spectroscopy techniques such as Surface Enhanced Raman Spectroscopy (SERS) and Surface Enhanced Fluoressence Spectroscopy which can be used to detect analytes with ultrahigh sensitivity. 

Ultra Uniform Gold Nanospheres

Our standard Au nanospheres have a variety of useful surface chemistries and narrow size distributions (CV < 15%), appropriate for a variety of applications ranging from lateral flow assays to optical coatings. Some applications, however, such as multiplexed dark field labeling or standards for nanoparticle size and shape, require even tighter tolerances on shape and size dispersity. For these applications, nanoComposix has successfully manufactured ultra-uniform, monodisperse gold nanospheres with sizes tunable from 10 nm up to 200 nm. As shown below, these gold nanoparticles have a nearly perfect spherical shape, smooth surfaces, and impressively narrow size distributions (CV < 6%, and for many sizes CV < 4%).

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Optical and Scattering Properties

Due to their high uniformity in size and shape, these Au nanospheres scatter a single color of light under dark field microscope imaging (shown below). The high purity of their light scattering signatures makes these nanospheres perfect scattering labels for imaging and building blocks for plasmonic nanostructures and devices.

Surface Chemistry

The gold nanospheres are stabilized with citrate in an aqueous solution. With their stable, easily displaceable surface chemistry, the gold nanospheres can be readily functionalized with a wide variety of molecules, including polymers and small molecules with desired functional groups, inorganic coatings such as silica, and biomolecules including DNA and antibodies for your application.

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Solvent Selection

To redisperse the particles, we recommend adding an appropriate solvent from the Table below to the dried powder and vortexing for 30 seconds. After redispersion, samples should be stored at 4°C and away from light, as described in our Storage and Handling instructions.

Solvent Refractive Index, nNanopowder 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

Effect of Solvent on Nanoparticle Optical Properties

UV-visible spectroscopy can be used to detect the presence of aggregation or changes in particle size; such effects are readily observed in the absorption spectrum as a change in the width of the plasmon peak and/or the appearance of a secondary peak that is red-shifted from the plasmon peak. Samples of a hexane dispersion of 4 nm-diameter dodecanethiol-coated Ag nanoparticles were dried and re-suspended in a variety of organic solvents. The absorption spectrum of the resuspended sample is compared with that of the original hexane dispersion in the figures below.

Comparison of the UV-visible spectrum of a dispersion of 4 nm dodecanethiol-coated Ag nanoparticles in hexane that have been dried and re-suspended in different organic solvents.

Small changes in the UV-visible absorption spectra of the redispersed samples are seen when compared with the original hexane dispersion. The shifting and broadening of the the spectra are typical of those seen during solvent transfer due to a change in the refractive index of the solvent, and are not due to changes in particle size or agglomeration.