Nano Flow produces and commercializes highly spherical and stable citrate-stabilized gold colloids specifically adapted to lateral flow test format. Their unique sphericity combined with their size homogeneity and their highly contrasting ruby color make Nano Flow Gold ideal for the development of rapid tests showing high sensitivity and precision.

Nano Flow Gold is manufactured by using a unique automated industrial manufacturing process allowing to produce gold nanospheres with unique size uniformity and sphericity

Our high-scale production units do allow the production of single batches till 100L- scale.

Our gold particles are synthesized using citrate reducing and stabilizing agent. Citrate salts weakly interact with nanogold by electrostatic interactions and therefore can be easily displaced by adding any biomolecules like antibodies, receptors, DNA, aptamers and any other proteins. Proteins, thanks to their chemical composition, create very strong and stable interactions with gold by combining different types of interactions like electrostatic, hydrophobic and coordinate covalent bounds. Optimizing the pH of your gold colloidal solution will ensure proper conjugation of any biomolecules.

Using Nano Flow Gold allows rapid test developers to reach high sensitivity and precision taking advantage of the high sphericity of our gold particles. When two spheres are in interaction, they generate a weak interaction energy due to their single contact point. On the opposite of particles containing sharp edges, the association of two spherical particles is reversible minimizing the appearance of aggregates. This maximizes the gold surface area to attach antibodies and reach outstanding sensitivities. The high monodispersity and the absence of any odd shapes in Nano Flow Gold make our gold colloids precursors of highly precision rapid diagnostic tests.

Why choose Nano Flow Gold

High sensitivity

Our highly spherical gold nanoparticles do not contain sharp edges particles reducing their aggregation rate and maximizing the contact surface available to immobilize a high number of antibodies. High sphericity means that all antibodies interacting with the gold surface are in the same environment with very limited steric hindrance. This makes for favorable association kinetics between antibodies and their corresponding antigen.

High precision

Nano Flow Gold colloids have the advantage to only present highly spherical and monodisperse particles with no odd shapes (e.g., triangles, hexagons…). All particles have the same size and morphology, so they will not bring any additional variability to your diagnostic assay.


Using Nano Flow Gold, you will be sure that all antibodies immobilized on colloidal gold will remain accessible for antigen binding. Using less costly antibody will allow substantial economies. In addition, our high-scale manufacturing units ensure you to benefit from highly competitive pricing while offering improved quality gold particles.


Considering the excellent monodispersity and the truly spherical shape of our gold nanoparticles, Nano Flow Gold offers unique shelf life of 18 months.


Well-dispersed and stable gold nanospheres give ruby red color to the colloidal gold suspension. This color, synonym of high-quality gold, reveals with high contrast test and control lines on nitrocellulose membranes.


Nano Flow Gold particles are available in different sizes for a maximum of flexibility. Single batch of gold nanoparticles are available at volumes exceeding 100 liters for reduced hands-on time linked to new batch implementation.

Product Features

40nm Gold colloids (Ref: NF-BG40) 20nm Gold colloids (Ref: NF-BG20)
Size 40+/-3 nm 20+/-3nm
OD 8 8
Sphericity 99+% 99+%
Odd shapes per 100 particles ≤1 ≤1
CV on particle sizes <13% <15%
Suspension water water
Single batch scale Max. 13L Max. 13L
Stability 18 months 18 months

All our gold nanoparticles production batches are supplied with a Certificate of Analysis to guarantee products meet specifications. This report includes Transmission Electronic Microscopy, Dynamic Light Scattering and UV-vis spectroscopy information.