New artificial ‘nose’ can detect spoiling food, hazardous gases

By Ashwini Sakharkar 22 Oct, 2024

Collected at: https://www.techexplorist.com/new-artificial-nose-detect-food-starting-spoil/91412/

Although historically, the sense of smell has been instrumental in combating diseases like the plague and tuberculosis, the human nose lacks the sensitivity required for reliable diagnostics. However, a new artificial ‘nose’ inspired by our olfactory system has the potential to detect undiagnosed diseases, hazardous gases, and spoiling food. This breakthrough is made possible by existing technology.

The ubiquitous technology in our daily lives—mobile phones, computers, and TVs—all share a common component: antennas.

According to Michael Cheffena, a telecommunications professor at NTNU in Gjøvik, these antennas can serve a purpose beyond communication. By equipping antennas with sensor functions, we can tap into new applications and expand the capabilities of existing infrastructure. This potential for innovation is a primary driver behind the exploration of antennas for non-traditional uses.

Cheffena emphasized that prior endeavors to develop “electronic noses” lacked the benefit of an existing readily available infrastructure. Additionally, they encountered numerous challenges that antenna technology has the potential to address.

“Other electronic noses can have several hundred sensors, often each coated with different materials. This makes them both very power-intensive to operate and expensive to manufacture. They also entail high material consumption. In contrast, the antenna sensor consists of only one antenna with one type of coating,” said Cheffena.

According to Yu Dang, their sensor boasts an impressive 96.7% accuracy in distinguishing between various gases, outperforming even the best electronic noses in some aspects. This cutting-edge technology works by transmitting radio signals at different frequencies and analyzing their reflections to create unique patterns linked to specific volatile organic compounds.

Volatile organic compounds (VOCs) are ubiquitous in the air, characterized by their low boiling points and ability to evaporate at low temperatures. Although invisible and imperceptible, you have likely encountered their distinctive odors.

All living organisms, including plants, emit VOCs as a means of defense against pests and for inter-organism communication. The familiar scent of freshly cut grass is a notable example.

Additionally, the petrol fumes emitted by your lawnmower are another illustration of VOCs in action. Given that many everyday products and materials also release VOCs, most environments contain a diverse array of these compounds, posing challenges in distinguishing significant gases from inconsequential ones.

This task becomes even more complex when isomers are included in the mix, as Dang explained.

“Isomers are chemical compounds that have the same molecular formula, but where the atoms are bound together in slightly different ways,” he said.

According to the researchers, they are a bit like twins: very similar, yet not identical.

“These compounds have long been a challenge for this type of sensor technology. Even the most sophisticated E-noses consisting of many different sensors struggle with them,” Dang said.

The sensor technology has been successfully tested on impact-damaged fruits and meats of different ages. By fine-tuning the algorithms to identify the distinct ‘fingerprints’ of various gases, the researchers are optimistic that the technology could also be utilized for disease detection.

“Volatile organic compounds enable trained dogs to detect health-threatening changes in blood sugar and diseases like cancer, so the principle is largely the same,” Dang said.

The antenna sensor is incredibly user-friendly and doesn’t necessitate extensive training or specialized handlers, unlike dogs. This technology is readily available in your living room.

Journal reference:

1. Yu Dang, Yenugu Veera Manohara Reddy, Michael Cheffena. Facile E-nose based on single antenna and graphene oxide for sensing volatile organic compound gases with ultrahigh selectivity and accuracy. Sensors and Actuators B: Chemical, 2024; DOI: 10.1016/j.snb.2024.136409