At the Instituto de Microelectrónica de Madrid, researchers have developed a tiny, cheap, portable sensor potentially capable of detecting HIV in people within a week of infection. These days nucleic acid amplification is the clinical standard, but it’s too expensive for many places around the world. Besides preventing early detection, not being able to screen blood for HIV hampers blood donation efforts.
Now researchers at the Instituto de Microelectrónica de Madrid have developed an immunoassay that, according to the study abstract in PLoS ONE “combines nanomechanical and optoplasmonic transduction methods” to detect the P24 capsid protein that HIV immunoassays look for.
The new immunoassay’s limit of detection is five orders of magnitude better than the last clinically approved immunoassays and even two orders better than nucleic acid amplification testing.
A bit of detail about the technology from the study abstract: The immunoreactions take place on the surface of a compliant microcantilever where gold nanoparticles are used as both mechanical and plasmonic labels. The microcantilever acts as both a mechanical resonator and an optical cavity for the transduction of the mechanical and plasmonic signals. The limit of detection of the immunoassay is 10−17 g/mL that is equivalent to one virion in 10 mL of plasma.