An optical biosensor capable of quickly detecting the virus that causes mpox — an infectious disease formerly known as monkeypox that can cause a painful rash, enlarged lymph nodes, fever, headache, muscle ache, back pain and low energy, among other symptoms — has been developed by researchers from the University of California San Diego School of Medicine and Boston University.

According to the researchers, the biosensor promises to enable clinicians to diagnose mpox quickly versus waiting long periods of time for lab results. Currently, polymerase chain reaction (PCR) is the only approved approach for diagnosing mpox, which is typically expensive, requires a lab and can take days or even weeks for results to return.

As such, the team used a digital detection platform called Pixel-Diversity interferometric reflectance imaging sensor (PD-IRIS) to detect the virus more rapidly.

The team tested the biosensor using samples collected from the lesions of a patient diagnosed with lab-confirmed mpox. These samples were briefly incubated with monoclonal antibodies specific to mpox, which bind to proteins on the virus's surface. The resulting virus-antibody complexes were then introduced into tiny chambers on silicon chip sensors, pre-treated to capture the nanoparticles.

By simultaneously directing precise wavelengths of red and blue light onto the chips, the team generated interference patterns that varied subtly in the presence of the virus-antibody nanoparticles. A color camera detected these minute signals, enabling highly sensitive counting of individual particles.

“You're not trying to see the scattered light from the virus particle itself, but you're looking at the interferometric signature of the field of scattered light mixed with the field that is reflected from the surface of the chip,” the researchers explained

Further, the team analyzed samples of the herpes simplex virus and cowpox virus — both of which have similar clinical presentations to mpox — with the team reporting that the biosensor assay easily discriminated mpox samples from those other viruses.

An article detailing the findings, “A label-free optical biosensor-based point-of-care test for the rapid detection of Monkeypox virus,” appears in the journal Biosensors and Bioelectronics.

To contact the author of this article, email mdonlon@globalspec.com