Updating our post of 3'2020, we note that Nano-Ditech now has 5 or 6 tests based on their nano-gold platform. As described in the official [instructions,](https://www.nanoditech.com/wp-content/uploads/2023/08/04-EUA220416.NanoCheck-COVID-19-Antigen-At-Home-Test-R0-IFU-HCP-05-12-2023.pdf)
the principle of the test is as follows:
"When specimens are lysed and added to the sample well of test device,
SARS-CoV-2 viral antigens present in the specimen bind to antibodies
against SARS-CoV-2 nucleocapsid conjugated to gold colloidal particles
and biotin in the test strip. The antigen-conjugate immunocomplexes
migrate across the test strip and are captured at the test line of nitrocellulose
membrane.
...Test results are visually interpreted at 15-30 minutes (but no later than 30
minutes). The presence of two pinkish red colored lines in the control line
“C” and test line “Ag” indicates COVID-19 positive. The presence of one
colored line in the control line “C” indicates COVID-19 negative."
In 2020, Nano Magazine reported important news about Covid-19 testing.
As many nations across the world are dealing with increasing numbers of coronavirus cases, the testing of suspected carriers is being intensified also. The mass expansion of testing means that nations are currently relying heavily on traditional technology, based on the tried-and-true polymerase chain reaction (PCR).
This increased pressure on current testing methods that require laboratory machines, means that it is vital alternative approaches can be found to make it easier and quicker for potential carriers to be tested and screened. Some methods modify the standard PCR test, to amplify small bits of genetic material to enable detection, whereas others sequence the virus directly or use the genome editor CRISPR.
Meanwhile, another form of test, widely used in China’s efforts to fight the spread of coronavirus, offers a quick point-of-care solution by detecting the IgM and IgG antibodies your body creates to naturally fight off the virus.
More at source.
While antibody testing does not tell whether the person is currently infected, it does report whether they have recently been exposed to the virus. This can be particularly useful as it provides information on people who have previously been exposed and have recovered, something virus detecting tests do not. It provides rapid results with positive results in as little as 3 minutes and 15 minutes for a confirmed negative result.
The tests in question use nanometer scale gold particles that have been used in a number of tests over the years for parasitic, virus, and fungus diseases; tuberculosis, melioidosis, syphilis, brucellosis, shigellosis, and coli-infections; to determine blood groups and pregnancy at an early stage, for dot blot hybridization, and for revealing the diphtheritic toxin, diagnostics of myocardial infarction, and hepatitis B. It has also been used for screening of early stage cancer and even to treat things like prostate cancer.