MOSCOW, September 25. /TASS/. Researchers from Russia and Germany have come up with a technique for assembling a highly-sensitive and selective gas sensor, which will enable it to precisely track dangerous substances in the air that are harmful to humans, Skoltech’s press office reported. The results of the study have been published in the journal Scientific Reports.
Gas sensors are required for monitoring the environmental conditions of a surrounding area. That said, they’re needed to detect gases harmful to people’s health. Therefore, this sensor must be very sensitive and selective in detecting a very tiny amount of any given dangerous substances and must be careful not to mix them up.
Now, to fine-tune the sensors’ precision, it is essential to increase the overall surface of the sensitive material which reacts with the gases under detection. To achieve this goal, the material (for instance, metal oxides) is split into smaller crystals. The downside to such sensors are their sensitivity to high temperatures and selectivity problems.
Researchers from Skoltech, Germany's Karlsruhe Institute of Technology, Yuri Gagarin State Technical University of Saratov, and V.A. Kotelnikov Institute of Radio Engineering and Electronics of the Russian Academy of Sciences suggested replacing those crystals with 2D structures - nanotubes comprised of titanium dioxide, assembled in ordered arrays. To help an analyzer distinguish between the different gases, the sensitive material was split into segments, with each of them differing slightly in properties from all others. The total aggregate of these signals of such a row of sensors under the impact of gas vapor can be considered as a "fingerprint" characteristic for a given substance.
"During the course of the laboratory studies, we checked the response of our system to air containing acetone, isopropanol, and ethanol vapors. The last two gases are chemically similar, but we managed not only to detect them, but also to define their type by "teaching" our system to identify the appearance of gas by its "fingerprint," commented Fedor Fedorov, the main author of the study and Skoltech research assistant.
Organic gases, particularly acetone, can serve as indicators of a person’s health condition. The amount of acetone in the air exhaled by a human, can be extremely high when such diseases as pancreatic diabetes, cancer and many others are present. Using the new technology, not only can you monitor the environmental conditions of a surrounding area, but you can also detect medical problems.