Domestic researchers have developed a technology that can detect acetic acid, a major cause of sick house syndrome.
Professor Kim Young-ki from Pohang University of Science and Technology (POSTECH) and his research team announced on the 24th that they have developed a liquid crystal-based sensor technology capable of selectively detecting harmful gases in the air in collaboration with researchers from Seoul National University and Gunsan University. The results of this study were published in the international journal Small.
The air contains various invisible gases. Among them are harmful substances like acetic acid, which causes sick house syndrome, making technology to accurately identify them essential. Until now, harmful gases have been detected by utilizing the properties of liquid crystals, which change according to the surrounding environment, through reflection or transmission of light. However, it has been limited in distinguishing specific gases in an environment where multiple gases are mixed.
To solve this problem, the research team added organic ion materials to the liquid crystals. Organic ion materials can be precisely designed in structure, allowing them to react selectively to specific gases.
The developed sensor reacted only to acetic acid, a major cause of sick house syndrome, and showed no influence from other gases. It demonstrated a high sensitivity capable of detecting even very small amounts of acetic acid at a level of 2 ppm (1 ppm is one millionth). Additionally, it distinguished reactions from propionic acid, which has a similar structure, proving its precise detection ability.
The research team analyzed the operating principle of the sensor not only through experiments but also through computer simulations. They theoretically clarified how liquid crystals and organic ion materials interact, revealing that adjusting the structure of the organic ion materials can predict and optimize sensor sensitivity.
Professor Kim Young-ki noted, "This research is a remarkable achievement in dramatically improving the selectivity, which was the greatest limitation of liquid crystal sensors," adding that it could be utilized for not only air quality management but also for real-time detection of specific gas leaks in semiconductor and chemical processes, as well as environmental monitoring systems.
References
Small (2025), DOI : https://doi.org/10.1002/smll.202410079