Scientists based at Pennsylvania State University (PA, USA) and New York University (NY, USA) have developed a rapid and label-free microfluidic platform that could be used to capture and identify viruses directly from clinical samples.
The research, published in PNAS, details the development and validation of a portable platform that contains carbon nanotube arrays – capable of capturing viruses by their size – coupled to Raman spectroscopy. The research reports that the new microfluidic device is capable of successfully identifying viruses in real time directly from clinical samples.
Viruses are responsible for a number of recent epidemic outbreaks, with known viruses such as H5N1, Ebola and Zika causing widespread illness and death. The early and accurate characterization of viral strains is a crucial step in the successful management of such outbreaks.
Co-author Mauricio Terrones (Pennsylvania State University) who worked on the development of the new microfluidic device, named the VIRRION, explained: “We have developed a fast and inexpensive handheld device that can capture viruses based on size. Our device uses arrays of nanotubes engineered to be comparable in size to a wide range of viruses. We then use Raman spectroscopy to identify the viruses based on their individual vibration.”
Due to the small size and low cost of the new microfluidic device it could prove to be useful in clinics across the world, including those in remote locations where outbreaks occur. Terrones explained: “Most current techniques require large and expensive pieces of equipment. The VIRRION is a few centimeters across. We add gold nanoparticles to enhance the Raman signal so that we are able to detect the virus molecule in very low concentrations. We then use machine learning techniques to create a library of virus types.” The viruses remain viable after capture and detection by the VIRRION chip and following purification can be subjected to subsequent in-depth characterization by conventional methods.
The team validated the new microfluidic device using different subtypes of avian influenza A viruses and human samples with respiratory infections, reporting the successful enrichment of rhinovirus, influenza virus and parainfluenza viruses. The device is also reported to maintain stoichiometric viral proportions when samples contain more than one type of virus, suggesting it could also be functional in cases where coinfection has occurred.
Viral capture and detection can be achieved in minutes, with a reported 70-fold enrichment and 90% virus specificity. The team hope that the new microfluidic device coupled to Raman virus identification constitutes an innovative system that could be used to quickly track and monitor viral outbreaks in real time.
Sources: Yin-Ting Y, Gulino K, Terrones M et al. A rapid and label-free platform for virus capture and identification from clinical samples. PNAS doi:10.1073/pnas.1910113117 (2019) (Epub ahead of print); https://news.psu.edu/story/602666/2019/12/23/research/fast-and-inexpensive-device-capture-and-identify-viruses