The novel detector comprises tiny gold particles deposited on a plastic support, enabling the analysis of the serum contained in the patient’s blood.
If the serum contains distinctive biological markers of disease, such as p24, linked to infection with the virus that triggers AIDS, and prostate-specific antigen (PSA) that serves for diagnosis of prostate cancer, then the gold nanoparticles react, providing a blue tint characteristic to this solution which is analyzed by the detector. In the absence of these markers, the particles separate to form tiny bubbles that give solutions a reddish coloring.
According to its inventors, the medical prototype is 10 times more sensitive than the previous tests and 10 times cheaper to manufacture. That should be enough to make poor countries interested in the new test.
“The test is designed on disposable plastic supports and does not require the use of expensive equipment, since the sought molecule can be detected at a quick glance with naked eye,” said Molly Stevens from Imperial College London.
The high sensitivity of this prototype ultra-sensitive sensor makes it suitable for early stage detection of an infection or a disease, when current methods fail, thus providing a greater chance of treatment, e.g. to HIV-positive patients.
“It is important for these patients to be tested periodically to assess the success of retroviral therapies and to detect new cases of infection,” said Roberto Rica, coauthor of the study, published today in the scientific journal Nature Nanotechnology.