60 nm Silver Shelled Gold Nanospheres

Product Number


  • Unagglomerated and monodisperse
  • Mean diameter: 60 nm ± 4 nm
  • Size distribution (CV) < 15%
  • Available as NanoXact, 0.02 and 1 mg/mL concentrations (total metal content)
  • Particles have a sodium citrate surface and are provided in aqueous 2 mM citrate

Product Lines

Tight Size
Wide Variety
of Surfaces
Guaranteed Sterile
& Endotoxin-Free
Learn more +
(certain products)

(certain products)
  • Monodisperse and unagglomerated
  • Standard colloidal concentration (~1 OD)
  • Seven standard surfaces (citrate, tannic, PVP, lipoic acid, PEG, BPEI, silica)

Which Surface Should I Choose?

Surface Displaceable Salt
Stable in
Stable in
Stable in
Polar Organics
Stable in
Non-Polar Organics
Conjugatable Charge
at pH 7
Citrate Learn more +
  • Most commonly requested capping agent
  • Easily displaceable with other molecules for binding studies or custom functionalization
  • High degree of electrostatic stabilization

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
N NanoXact, 0.02 mg/mL Citrate Download ↓ BMCN60-25M $57+
N NanoXact, 0.02 mg/mL Citrate Download ↓ BMCN60-100M $185+
N NanoXact, 0.02 mg/mL Citrate Download ↓ BMCN60-500M $650+
N NanoXact, 0.02 mg/mL Citrate Download ↓ BMCN60-1000M $1,025+
N NanoXact, 1 mg/mL Citrate Download ↓ BMCH60-1M $225+
N NanoXact, 1 mg/mL Citrate Download ↓ BMCH60-5M $950+
N NanoXact, 1 mg/mL Citrate Download ↓ BMCH60-10M $1,625+
N NanoXact, 1 mg/mL Citrate BMCH60-30M $3,450+

Need help reading our Certificates of Analysis? +


Bimetallic Au-core/Ag-shell nanospheres are available in size ranging from 20 to 80 nm in diameter. The particles are stabilized with sodium citrate (2 mM) and are provided at 0.05 mg/mL or 1 mg/mL (total metal content).

Total Diameter (nm)Gold Core Diameter (nm)Silver Shell Thickness (nm)Au Mass %Ag Mass %Plasmon Resonance Peak (nm)



Due to the unique optical properties of gold and silver, the bimetallic nanoparticles have a tunable peak resonance wavelength that is a function of the size of the gold core and the thickness of the silver shell.

The optical properties of the bimetallic particles are different than for solid silver or solid gold of the same diameter. Normalized UV-visible extinction spectra for bimetallic and solid silver and gold nanoparticles are shown below.


Toxicologist have performed hundreds of studies on our silver nanoparticles to understand how the size, shape, and surface of silver nanoparticles affects the environment and human health. Bimetallic Au@Ag nanoparticles are an additional tool to understand fate and transport in biological systems by providing definitive information about the dissolution state and ultimate fate of the particles. Transmission Electron Microscopy images in tissue slices can show the rate of structure of silver dissolution as well as locate the gold core which will remain intact during experiments. ICP-MS analysis can measure the ratio of silver to gold, providing additional information on dissolution rates and nanoparticle fate and transport.

Single Particle ICP-MS

Bimetallic nanomaterials can be used as standards or tracer materials in single particle inductively coupled plasma mass spectroscopy (SP-ICP-MS) studies. Our highly uniform samples contain particles with low particle-to-particle variation in the Au:Ag ratio. Further, during dissolution studies where some of the silver may dissolve into solution, the more stable gold core provides a constant mass signal that can be used to help determine particle size and a check of the starting particle concentration in a sample.

Custom Synthesis

Need a different size, Au/Ag ratio, or surface? We offer custom synthesis services for the fabrication of a bimetallic particle to your specifications.