ΒιΆΉΣ³»΄«Γ½ researchers have developed a device that detects viruses like COVID-19 in the body as fast as and more accurately than current, commonly used rapid detection tests.
The optical sensor uses nanotechnology to accurately identify viruses in seconds from blood samples. Researchers say the device can tell with 95% accuracy if someone has a virus, a significant improvement over current rapid tests that experts warn could have low accuracy. Testing for viruses is important for early treatment and to help stop their spread.
The results are detailed in a newΒ study in the journal Nano Letters.
The researchers tested the device using samples of Dengue virus, a mosquito transmitted pathogen that causes Dengue fever and is a threat to people in the tropics. However, the technology can easily be adapted to detect other viruses, like COVID-19, says study co-author Debashis Chanda, a professor in ΒιΆΉΣ³»΄«Γ½βs
βThe sensitive optical sensor, along with the rapid fabrication approach used in this work, promises the translation of this promising technology to any virus detection including COVID-19 and its mutations with high degree of specificity and accuracy,β Chanda says. βHere, we demonstrated a credible technique which combines PCR-like genetic coding and optics on a chip for accurate virus detection directly from blood.β
The device closely matches the accuracy of the gold-standard PCR-based tests but with nearly instantaneous results instead of results that take several days to receive. Its accuracy is also a significant improvement over current rapid antigen tests that the U.S. Food and Drug Administration and U.S. Centers for Disease Control have cautioned could produce inaccurate results if viral loads are low or test instructions are not properly followed.
The device works by using nano-scale patterns of gold that reflect back the signature of the virus it is set to detect in a sample of blood. Different viruses can be detected by using different DNA sequences that selectively target specific viruses.
Key to the deviceβs performance is that it can detect viruses directly from blood samples without the need for sample preparation or purification, thus speeding up the test and improving its accuracy.
βA vast majority of biosensors demonstrations in the literature utilize buffer solutions as the test matrix to contain the target analyte,β Chanda says. βHowever, these approaches are not practical in real-life applications because complex biological fluids, such as blood, containing the target biomarkers are the main source for sensing and at the same time the main source of protein fouling leading to sensor failure.β
The researchers confirmed the deviceβs effectiveness with multiple tests that used different virus concentration levels and solution environments, including those with the presence of nontarget virus biomarkers.
Abraham Vazquez-Guardado, the studyβs lead author and a postdoctoral fellow at Northwestern University who worked on the research as a doctoral student in Chandaβs lab, says heβs excited about the potential.
βAlthough there have been previous optical biosensing demonstration in human serum, they still require off-line complex and dedicated sample preparation performed by skilled personnel β a commodity not available in typical point of care applications,β Vazquez-Guardado says. βThis work demonstrated for the first time an integrated device which separated plasma from the blood and detects the target virus without any pre-processing with potential for near future practical usages.β
Chanda says next steps for the research include adapting the device to detect more viruses.
Study co-authors are Freya Mehta, Beatriz Jimenez, Keval Ray, Aliyah Baksh β undergraduate students at NanoScience Technology Center; Aritra Biswas β21MS β a doctoral student with ΒιΆΉΣ³»΄«Γ½βs College of Optics and Photonics; Sang Lee β16Β β a masterβs student at the NanoScience Technology Center; Nileshi Saraf β a graduate of ΒιΆΉΣ³»΄«Γ½βs doctoral program; and Professor Sudipta Seal βchair of ΒιΆΉΣ³»΄«Γ½βs Department of Material Science and Engineering.
Chanda has a joint appointment in ΒιΆΉΣ³»΄«Γ½βs Department of NanoScience Technology Center, the and the College of Optics and Photonics. He received his doctorate in photonics from the University of Toronto and worked as a postdoctoral fellow at the University of Illinois at Urbana-Champaign before joining ΒιΆΉΣ³»΄«Γ½ in 2012.
The research was partially supported by National Science Foundation and ΒιΆΉΣ³»΄«Γ½βs COVID-19 Artificial Intelligence and Big Data Initiative program.
