Spherical Gold Nanoparticles (SAuNPs) – 15nm

 32 1,035


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  • To design different OD of this product or for bulk quantities, submit your request here.

  • To obtain a different size and shape of gold nanoparticles or to design other nanomaterials, submit your request here.

Product Specification

Parameters OD : 1 OD : 10 OD : 50
Diameter (TEM) (nm) 14.83 Same Same
Size disparity (+/- nm) 2.84 Same Same
Diameter deviation 15% Same Same
SPR Peak 537 – 540 Same Same
Particle concentration (NP/mL) 1.27E + 12 1.27E + 13 6.35E + 13
Mass concentration (mg/mL) 4.17E – 2 4.17E – 1 2.09E + 00
Particle molar concentration 2.19E – 9 2.19E – 8 1.05E – 07
Zeta potential (mV) -26.2 Same Same
Zeta potential deviation 10% Same Same
Particle volume (nm3) 1.71E + 3 Same Same
Particle surface (nm2) 6.31E + 02 Same Same
Surface/Volume Ratio 0.404 Same Same
Solvent Water Same Same
Stability 3 months Same Same
Storage temperature 4 – 8 °C Same Same
Color Purple-red Same Same

Physico-chemical Characterization

Gold Nanoparticles 15nm Graph - 1

Extinction spectrum of the solution of SAuNPs 15

Gold Nanoparticles 15nm Graph - 2

Size distribution of SAuNPs 15 determined by transmission electron microscopy image

The unique properties of TORSKAL’s gold nanoparticles:


We employ an environmentally friendly technique for the production of well-characterized gold nanoparticles.

Salt resistance

Stable over 0.4 M NaCl, which is 5 times higher than gold nanoparticles synthesized by the citrate reducing method.


Our process of producing gold nanoparticles or colloidal gold is very straightforward to scale up with a lower risk of contamination.


Our green synthesis process does not require toxic chemicals, which makes our products suitable for biomedical applications.

High purity

Our gold nanoparticles are of high purity with the absence of aggregation, which makes them monodisperse gold nanoparticles.

High stability – For at least 3 months

Our gold nanoparticles are more stable than Turkevich gold nanoparticles in a saline environment, over time, and after centrifugation.

Our Publications:

Turkevich vs TORSKAL’s gold nanoparticles

Since colloidal suspensions are thermodynamically unstable and tend to flocculate, the control of the aggregation of gold nanoparticles is important to modulate their applications. For biomedical applications, poor stability can lead to a total or partial loss of their nanoscale properties, alters their cellular uptake, and modifies their bioavailability and toxicity.

Colloidal stability is a result of attractive Van der Waals and repulsive electrostatic forces between particles preventing them from aggregation. The sum of these opposing forces results in a total interaction potential depending on the distance between two particles whereby the maximum is referred to as the aggregation barrier. These interactions can be influenced by environmental parameters such as pH, temperature, ionic strength, and the presence of ligands.

This experiment illustrates the high sensitivity of the coloration to compare gold nanoparticles’ stability: Individual gold nanoparticles appear red/red-purple; however, when the particles aggregate together, the plasmon resonances shift, and the color changes to blue. Upon addition of PBS to Turkevich nanoparticles, the initially red color of the gold nanoparticles solution turn to blue. Salts in PBS screen the repulsive electrostatic forces caused by the citrate layer: indeed, the positive charges of the electrolyte associate with the negative charges on the surfaces of the nanoparticles. However, TORSKAL’s gold nanoparticles showed remarkable stability in the same condition, which makes them monodisperse.

Turkevich vs TORSKAL's Gold Nanoparticles

Turkevich vs TORSKAL’s AuNPs

Product Summary

Gold nanoparticles are one of the most widely used nanomaterials for academic research, point-of-care medical devices and industrial products due to their stability, optical properties and multiple surface functionalities. The optical and electronic properties of gold nanoparticles are tunable by changing the size, shape, surface chemistry, or aggregation state. Chemical reduction is the most popular method to synthesize well defined metallic nanoparticles. Although this method offers significant advantages of simple equipment and convenient operation, it involves the use of toxic, hazardous chemicals, which may pose potential environmental and biological risks.

The gold nanoparticles or colloidal gold offered by TORSKAL are produced by green chemistry (by bio-reduction of metal salts HAuCl4), with crude and / or purified extracts from plants. These extracts have the double action of reducing the metal and stabilizing the nanoparticle formed. The size and shape of the nanoparticles formed can be modulated by various factors during the synthesis. The synthesis of nanoparticles by using the bio-reducing potential of plant extracts has been demonstrated in various studies in recent years. Based on this observation, TORSKAL developed a green chemistry approach to synthesize nanoparticles using endemic plants originated from Reunion Island. Plants extracts have the double action of reducing the metal and stabilizing the formed nanoparticles.

Each batch of gold nanoparticles or colloidal gold are fully characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta-potential, XRD, UV-Vis, FTIR and Raman spectroscopy to understand their physicochemical and biological properties.

Our Products Are

Fairmined Licensed Brand

Fairmined certified

Our gold nanoparticles are designed from ethical gold sourced from Fairmined, a responsible mining community.



We use a green chemistry approach to synthesize nanoparticles from plants endemic to Reunion Island.

TORSKAL's Gold Nanoparticles synthesized from green chemistry, lyophilised plant extract, plant powder and dried plant leaves

TORSKAL’s AuNPs synthesized from green chemistry, lyophilised plant extract, plant powder & dried plant leaves

Applications of our gold nanoparticles:

  • Photothermal Therapy, Photodynamic Therapy

  • Diagnostics, Drug Delivery

  • Lateral Flow Analysis (LFA)

  • Light Microscopy, Darkfield Microscopy

  • Electron Microscopy (TEM/SEM)

  • Surface-Enhanced Fluorescence

  • Surface Enhanced Raman Spectroscopy (SERS)

  • Biosensors, Biomarkers

  • Plasmonic, Nanocoating

  • Catalysis, Electronics

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