Strict sense of smell is a powerful ability shared by many organisms. However, it has been shown to be difficult to repeat by artificial means. The researchers combined biological elements and engineering to create what is known as a biohybrid component. Their volatile organic compound sensors can physically detect odors. They hope to improve the concept of medical diagnosis and the detection of hazardous materials.
Electronic devices such as cameras, microphones, and pressure sensors allow machines to perceive and quantify their surroundings optically, acoustically, and physically. Our sense of smell, however, is one of the main senses of nature, but it has been shown to be very difficult to repeat artificially. Evolution has refined this sense over millions of years and researchers are working hard.
Strict sense of smell is a powerful ability shared by many organisms. However, it has been shown to be difficult to repeat by artificial means. The researchers combined biological elements and engineering to create what is known as a biohybrid component. Their volatile organic compound sensors can physically detect odors. They hope to improve the concept of medical diagnosis and the detection of hazardous materials. Credit: © 2020 AAAS / Takeuchi et al.
“Smells, chemical signatures in the air, can provide useful information about the environments or samples being studied. However, this information is not well exploited due to the lack of sensors with sufficient sensitivity and selectivity, “said Professor Shoji Takeuchi of the University of Tokyo’s Biohybrid Systems Laboratory.” Biological organisms use odor information very efficiently. we decided to combine them directly to create sensors for highly sensitive volatile organic compounds (VOCs), which we call these biohybrid sensors. “
Takeuki and his team inserted a set of odor receptors from an insect into a device that feeds certain odors to the recipients, and reads how the receptors respond to those odors. Analysis of electrical signals from olfactory receptors indicates which molecules triggered the signals. This method provides high sensitivity and is possible thanks to the way the receptors physically bind to double lipids. In previous experiments, this method has limited the way smells are sent to receptors, but the team has also provided an effective solution to this problem.
“Recipients react to molecules in a liquid droplet, so one of the main challenges was to make a device to transplant the molecules from their air into those drops,” Takeuchi said. “We have designed and fabricated microscale droplet slots to force this molecular exchange where the droplet passes. By introducing gas into the microslite, we were able to increase the probability of contact between the gas and the droplet and efficiently transfer the target molecules to the fluid. ”
With this system, the researchers were able to detect traces of the chemical octenol, also called fungal alcohol, which is known to attract mosquitoes to the subject’s breath. Not only that, but the VOC sensor can detect concentrations in the order of trillion pieces. This is a thousand times less than the sensitivity of the dog’s nose, but it’s an impressive achievement nonetheless, and has encouraged the team to continue to innovate.
“I would like to expand the analytical side of the system using a kind of AI. This will allow our biohybrid sensors to detect more complex types of molecules,” Takeuchi said. “Such improvements can help us measure hazardous materials and environmental hazards in our goals, as well as measure the early stages of patients’ breathing and body odor diseases.”
Reference: Tetsuya Yamada, Hirotaka Sugiura, Hisatoshi Mimura, Koki Kamiya, Toshihisa Osaki and Shoji Takeuchi, January 13, 2021, “highly sensitive VOC detectors, with intensity odor receptors, regenerated in double lipids.” Advances in science.
DOI: 10.1126 / sciadv.abd2013
This research is partly sponsored by the Organization for New Energy and Industrial Technology Development (NEDO) in Japan JSPS KAKENHI JP16H06329 Scholarship Number, Japan’s MEXT Regional Innovation Ecosystem Program.