Researchers at the the Kanagawa Institute of Industrial Science and Technology, Gunma University, and the University of Tokyo have published details of a high-sensitivity biohybrid olfactory sensor — effectively, a tiny electronic nose.
“Odors, airborne chemical signatures, can carry useful information about environments or samples under investigation. However, this information is not harnessed well due to a lack of sensors with sufficient sensitivity and selectivity," explains corresponding author Professor Shoji Takeuchi of the problem the team set out to address.
"On the other hand, biological organisms use odor information extremely efficiently. So we decided to combine existing biological sensors directly with artificial systems to create highly sensitive volatile organic compound (VOC) sensors. We call these biohybrid sensors."
The sensors combine biological material — olfactory receptors taken from an insect — and an electronic device which feeds odors to the receptors and reads back their responses.
"The receptors react to molecules in a liquid droplet, so one of the main challenges was to make a device to transplant molecules from their air into these droplets," Professor Takeuchi explains. "We designed and fabricated microscale slits underneath where the droplet passes to force this exchange of molecules. By introducing the gas into the microslit, we were able to increase the probability of contact between the gas and the droplet and transfer target molecules to the fluid efficiently.
"I would like to expand upon the analytical side of the system by using some kind of AI. This could enable our biohybrid sensors to detect more complex kinds of molecules. Such refinements might help in our goals to not only measure hazardous materials and environmental hazards but maybe even early stages of diseases from patients’ breath and body odor."
The team's work has been published under open-access terms in the journal Science Advances.