Gold Nanoparticles are used in the COVID-19 antigen tests as in many others similar tests. The Au functionalized nanoparticles will capture the anti-bodies, and migrate on a cellulose strip, until being fixed on the test-line or the control-line. But what is the size of the nanoparticles? Small-Angle X-Rays Scattering gives us the answer: 28 ± 8 nm!
We unmounted a COVID-19 test, and measured the cellulose strip on the control line after migration. The protocols developed in our research works within the NIMBE/LIONS laboratory, enabled us to determine the size distribution. Very nice experiment to show what is the use of gold nanoparticles in the everyday life, and the powerful of SAXS. #CEA #SAXS #Nanoparticles #GoldNanoparticles #CEASaclay.
NB : The gold nanoparticles are trapped within the cellulose band of the COVID-19 test. They are not present on the cotton swab. If the test box is badly recycled, the eventually dispersed gold nanoparticles do not induce pollution. They are biocompatible, i.e. they do not generate toxicity at the organism level.
Contacts CEA : Olivier Taché et Fabienne Testard – Laboratoire NIMBE/SAXS.