Portable biosensor can detect bird flu in the air in less than five minutes

As H5N1 highly pathogenic influenza continues to extend in the US, presenting serious threats to dairy and poultry farms, both farmers and public health experts need better ways to monitor infections, in real time, mitigate and respond to outbreaks. Now, thanks to the research of the University of Washington in St. Louis published In a special number of ACS sensors In “Breath sensing”, virus trackers have a way to monitor H5N1 aerosol particles.

To create their Aviar influenza sensor, Rajan Chakrabarty laboratory researchers, Professor of Energy Engineering, Environment and Chemistry at the McKelvey School of Washu, worked with electrochemical capacitive biosensors to improve the speed and sensitivity of virus and bacteria detection.

His work is crossed crucially since the aviar virus has taken a dangerous turn during the past year to transmit through particles in the air to mammals, including humans. The virus has proven deadly in cats, and there has been at least one case of H5N1 human death.

“This biosensor is the first of its kind,” said Chakrabarty, speaking of the technology used to detect virus particles and air bacteria. Scientists previously had to use slower detection methods with polymerase chain reaction DNA tools.

Chakrabarty said conventional test methods can take more than 10 hours, “too much time to stop an outbreak.”

The new biosensor works in five minutes, preserving the sample of the microbes for a subsequent analysis and providing a range of pathogen concentration levels detected in a farm. This allows immediate action, said Chakrabarty.

Time is the essence by avoiding a viral outbreak. When the laboratory began working in this research, H5N1 was only transmissible through contact with infected birds.

“As this document evolved, so did the virus,” Chakrabarty added.

The United States traces the health of animals and pathogen outbreaks on farms through the Animal and Vegetable Health Inspection Service of the United States Department of Agriculture (APHIS), which for the last time that in the last 30 days, there have been at least 35 new cases of H5N1 dairy cattle in four states, mainly in California.

“The strains are very different this time,” said Chakrabarty.

If farmers suspect disease, they can send the animal to the laboratories of the State Agriculture Department for proof. However, it is a slow process that can be delayed even more due to the accumulation of cases, since H5N1 advances to birds of birds and dairy. Mitigation options include biosafety measures, such as quarantine animals, disinfection facilities and equipment, and protection controls to limit exposure to animals, including mass sacrifice. The USDA also recently issued a conditional license for a avian flu vaccine, which could provide greater relief to poultry farmers anxious to reduce egg prices.

Chakrabarty is ready to present this biosensor to the world and said it was built to be portable and affordable for mass production.

How it works

The integrated pathogenic sampling detection unit is approximately the size of a desk printer and can be placed where the farms vent the exhaust of chicken or cattle house. The unit is a wonder of interdisciplinary engineering that consists of a “sample of humid cyclone bioaerosol” that originally developed for SARS-COV-2 aerosols sampling.

The air loaded with pathogens enters the sample at very high speeds and is mixed with the fluid that covers the walls of the sample to create a superficial vortex, thus catching virus aerosols. The unit has an automated pumping system that sends the sampled fluid every five minutes to the biosensor for the detection of seamless virus.

The main scientist of Chakrabarty, Meng Wu, together with the graduate student Joshin Kumar, performed the laborious task of optimizing the surface of the electrochemical biosensor to increase its sensitivity and stability for the detection of the virus in small amounts (less than 100 copies of viral RNA per cubic meter of air).

The Biosensor uses “capture probes” called Scappers, which are individual DNA strands that bind to virus proteins, marking them. The great challenge of the team was to find a way to make these stables work with the surface of 2 millimeters of a naked carbon electrode to detect pathogens.

After months of proof and error, the team discovered the correct recipe to modify the carbon surface using a combination of graphene oxide and Prussian blue nanocrystals to increase the sensitivity and stability of the biosensor. The final step involved linking the electrode surface modified to the skipper through gluteraldehyde of reticulation, that Xu and Kumar said it is the “secret sauce” to functionalize the surface of a bare carbon electrode to detect H5N1.

They added that a great advantage of the equipment of detection of the equipment is that it is not destructive. After testing the presence of a virus, the sample could be stored for subsequent analysis through conventional techniques such as PCR.

The Integrated Pathogen Sampling Unit works automatically: a person does not need to have biochemistry experience to use it. It is made with affordable and easy to produce materials. Biosensor can provide H5N1 concentration ranges in air and alert operators on real -time disease peaks. Xu said that the knowledge of the levels can be used as a general indicator of “threat” in an installation and that the operators know if the balance of pathogens has been inclined to dangerous levels.

That ability to offer a range of virus concentration is another “first” for sensor technology. The most important thing is that it can potentially climb to find many other dangerous pathogens on a device.

“This biosensor is specific to H5N1, but it can be adapted to detect other influenza virus strains (eg” we have demonstrated these capabilities of our biosensor and inform the findings in the document. “

The team is working to market biosensor. Varro Life Sciences, a St. Louis biotechnology company, has consulted with the research team during the Biosensor design stages to facilitate its possible commercialization in the future.