Gold Colloids

Medical Uses

Gold Colloids

TANAKA offers high-quality products with prompt and thorough support.

Through our own proprietary processes, we have been able to produce gold nano particles that enable diagnostics and biosensors to be manufactured, which we supply using a high quality management system.

Gold-Citric Acid Colloidal Solution


  • Colloid solution in which nanosized gold particles are dispersed
  • Spherical gold particles with high-purity and a narrow particle size distribution
  • Easy to modify gold particle surfaces
  • Colloids can be supplied in the quantity and in the time required as they are manufactured in Japan
  • Colloids can be supplied at a stable level of quality with little variation between lots
Gold-Citric Acid Colloid 15nm


Gold-Citric Acid Colloid 30nm


Gold-Citric Acid Colloid 40nm


Gold-Citric Acid Colloid 50nm


Gold-Citric Acid Colloid 80nm


Gold-Citric Acid Colloid 100nm



Gold-citric acid colloidal solution is used in in-vitro diagnostic and other test kits.
It is ideal for use in test reagents, biomarkers, X-ray identification markers, etc.

Typical characteristics

Au colloid solution-SC
Particle size
Solvent Color Shape Particle size range Gold content (Wt%) pH
5 Water Light orange

Dark red
Spherical shape 10% or less in relation to the particle size 0.004~0.005 4.5
15 0.006~0.007 5.5
20 5
30 4
40 3.5
50 3
60 3
80 3
100 3
150 3
[Absorbance comparison graph] 5nmΦ~100nmΦ


[Au particle size comparison graph] 5nmΦ~100nmΦ

Au particle size