Rapid Detection on a Chip
Revolutionary Optical Biosensor Helps Slash Monkeypox Diagnosis Times
by Tyler Nguyen
A deadly variant of human mpox has swept through the Democratic Republic of Congo over the last couple of years, resulting in the deaths of approximately 5% of those reported as infected. As the disease spread to other neighboring countries, the World Health Organization declared the outbreak a Public Health Emergency of International Concern on August 14th, 2024. Currently, the international community lacks the resources for fast, cost-effective diagnostic tools to curb the spread of mpox, or indeed, any potential future global pandemic.
To address this deficit, Distinguished Professor of Engineering Selim Ünlü has developed an optical biosensor, in collaboration with researchers from UC San Diego School of Medicine. This technology enables rapid detection of the monkeypox virus at the point of care, eliminating the need to wait for lab results. The study’s findings were published in Biosensors and Bioelectronics, first-authored by current BU ECE Ph.D. student Mete Aslan.
A Searchlight for Virus Detection
Leveraging digital detection platform Pixel-Diversity Interferometric Reflectance Imaging Sensor, or PD-IRIS, to detect the virus, the study involved incubating lab-confirmed mpox samples with monoclonal monkeypox antibodies provided by co-PI Partha Ray of UC San Diego. The samples were then transferred into tiny chambers on the surface of silicon chips on PD-IRIS that were printed with proteins to capture these nanoparticles.
Precise wavelengths of red and blue light were shined simultaneously on the chip. This interference resulted in slightly different responses when virus-antibody nanoparticles were present. A color camera detected the small signal and the amount of individual particles with high sensitivity. The process is analogous to that of an FM radio mixing weak signal containing information with a more powerful carrier signal at the same frequency, which amplifies the weak signal.
Towards an End to an Epidemic – and Beyond
The study demonstrates extremely accurate results, easily discriminating mpox samples from other viruses like herpes simplex and cowpox virus samples; both of which have similar clinical presentations to mpox. The process also provided diagnosis in just twenty minutes, an exponentially significant improvement over the time required for sending samples to a lab.
This technology has the potential to substantially slow community spread of mpox in countries where healthcare resources are sparse. Even better, a boxed kit could not only be used for mpox, but a variety of viruses, such as syphilis or HIV, with the only change being the antibody that is mixed with a particular virus. The research team is working towards commercialization; with government support, they hope the mpox epidemic can be curbed before it can expand past the scope of the African continent.
Distinguished Professor of Engineering Selim Ünlü has been a member of the BU Electrical and Computer Engineering faculty since 1992. He is a Fellow of AIMBE, Optica, and IEEE, and the Founder and CEO of iRiS Kinetics.