The number of medicinal applications for gold seem to be increasing all the time – with promising initial results. Nanotechnology is at the forefront of these advancements, and although the field has only recently been in the public eye, it’s actually much older than you might think. In fact, before finding ways to treat diseases with gold, doctors had already found ways to detect medical conditions and diseases with gold nanoparticles.
One of the most well-known and earliest-developed diagnostic tests that uses gold nanoparticles is the common pregnancy test. In the early stages of pregnancy, the body produces the hCG (human chorionic gonadotropin) hormone – which is made up of two components. The testing strip contains one of these components, as well as gold nanoparticles that are bound to monoclonal antibodies. If the urine being tested contains hCG components, the antibodies will bind to one of the components, then seep down into the next layer of the test where the other component of hCG is contained. When the two components bind together, the gold nanoparticles are still attached – which creates the red-colored positive indicator.
This gold-based technology has been adapted to create a number of rapid diagnostic tests (RDTs) that have saved many lives. Similar RDTs that use gold nanoparticles include tests for malaria, HIV, cancer, and influenza.