Summary: Researchers have developed a versatile and low-cost quantitative testing system using Janus particles to rapidly detect viral proteins, with potential applications extending beyond COVID to diseases like influenza and hepatitis.

Takeaways:

  1. The new “Express Biochecker” system provides a rapid, simple, and low-cost method for detecting viral proteins using Janus particles and microfluidic technology.
  2. The system’s versatility allows it to be adapted for detecting biomarkers in other diseases, opening new avenues in medical diagnostics.
  3. Researchers aim to expand the system’s applications to measure various disease markers, making it a promising tool for broader diagnostic use in the future.

The importance of testing for diseases was thrust into the limelight during the COVID-19 pandemic, with PCR (polymerase chain reaction) or ELISA (enzyme-linked immunosorbent assay) testing becoming ubiquitous to the public eye.

Yet these forms of testing are far from perfect. They require large sample volumes, involve complex procedures, and even pose a risk of exposing the tester to the virus.

COVID Testing and Beyond

Now, a group of researchers has developed a new quantitative testing system called the “Express Biochecker,” which provides a simple, rapid, and low-cost method for detecting the coronavirus N protein. This new system, which incorporates advanced microfluidic technology, is not limited to the coronavirus; it is expected to be applied to other viral illnesses such as influenza and hepatitis in the future.

“Our novel immunoassay system is based on Janus particles, which, much like the Roman god they are named after, possess two ‘faces’ or sides,” says Hiroshi Yabu, principal investigator and deputy director of the Open Innovation Center of Hydrogen Science for Green Transformation at Tohoku University’s Advanced Institute for Materials Research (WPI-AIMR). “One side is coated with a fluorescent dye, and the other with magnetic particles and antibodies.” 

These particles are engineered to bind specifically to target antigens, such as viral proteins, and can be used in conjunction with antibody-immobilized microfluidic devices for highly precise measurements.

“The strength of this system lies in its versatility,” added Eiichi Kodama, a professor at the International Research Institute of Disaster Science at Tohoku University. “Not only can it be used for viral detection in other diseases, but it also has the potential to be adapted for measuring other biomarkers related to various conditions. This could open new avenues for medical diagnostics.”

The next phase of research will focus on expanding the system’s applications to include the detection of other disease markers.

Details of the findings were published in the journal Langmuir on Aug. 15, 2024. Also included in the research team was Professor Kentaro Totsu of the Micro System Integration Center, and Haplo Pharma Inc. (headquartered in Sendai, led by President Yoshihiro Otaki), which develops diagnostic devices for medical and healthcare applications.

Featured image: Transmission electron microscopy (TEM) image and fluorescence image of fluorescent magnetic Janus particles (top left), Schematic diagram of N protein detection using antibody-conjugated fluorescent magnetic Janus particles (top right), External view of the Express Biochecker developed in this research (bottom left), and Measurement results of N protein concentrations for the novel coronavirus (CoV-2, yellow) and a different coronavirus (229E, blue) (bottom right). Photo: Hiroshi Yabu