An intense sense of smell is a powerful ability that many living things possess. However, it has proven difficult to replicate by artificial means. Researchers have combined biological and synthetic elements to create what is called a biohybrid component. The VOC sensor can effectively detect the gas odors. They hope to refine the concept for medical diagnosis and the discovery of dangerous substances.
Electronic devices such as cameras, microphones, and pressure sensors enable machines to record visual, audio, and physical records and determine their surroundings. However, our sense of smell, despite being one of nature’s most primitive senses, has proven very difficult to artificially reconstitute it. Evolution has refined this meaning over millions of years, and researchers are working hard to catch up.
Professor Shuji Takeuchi of the University’s Biosystems Laboratory says, “Smells, and chemical signatures in the air, can contain useful information about the environment or samples being examined. However, this information is not well used due to the lack of sensors with sufficient sensitivity and selectivity. Tokyo. “On the one hand, organisms use scent information very efficiently. That is why we decided to integrate existing biological sensors directly with synthetic systems to create highly sensitive volatile organic compounds (VOC) sensors. We call these biosensors a hybrid.”
Basically, Takeuchi and his team grafted a set of insect olfactory receptors into a device that feeds the receptors with specific scents and also reads how the receptors respond to those scents. Analysis of the electrical signals from the olfactory receptors illustrates the molecules that trigger the signals. This method is very sensitive and can be accomplished by the way that the receptors actually bind in lipid bilayers. In previous experiments, this method limited the way smells could be delivered to receptors, but the team also found an effective solution to this problem.
“The receptors respond to the molecules in a liquid droplet, so one of the biggest challenges was building a device to transport particles from the air to these droplets,” Takeuchi says. “We designed and made small cracks underneath the droplet to force this exchange of particles. By introducing the gas into the microgap, we were able to increase the likelihood of gas-droplet contact and efficiently introduce target molecules into the transport liquid.”
Using this system, researchers were able to detect traces of the chemical octinol, also known as mild alcohol, which is known to attract mosquitoes, in the test person’s breath. And not only that: the VOC sensor can detect concentrations in the order of a billionth. That’s about a thousand times less than the sensitivity of a dog’s nose, but it’s still an impressive feat that has inspired the team to keep innovating.
“I want to expand the analytical side of the system using some kind of artificial intelligence,” says Takeuchi. “This could allow our bio-hybrid sensors to detect more complex types of molecules.” “These improvements can help us measure not only hazardous substances and environmental hazards, but possibly even early stages of disease based on the patient’s breathing and body odor.”
