At the University of Illinois, researchers have developed small, extremely sensitive detectors of volatile organic compounds, seemingly capable of sensing such chemicals at concentrations even our noses can’t detect. While there are a lot of applications for such technology in medicine and other fields, the researchers chose to detect ammonia in exhaled breath, a biomarker for kindey disease, as a proof of concept for the sensors.
The devices, made of porous thin films of organic semiconductors, are much smaller than existing bench-top products used to measure organic compounds in exhaled breath. They’re also cheap to produce, and if proven in trials may end up serving as disposable sensors that patients can take home with them, for example.
While organic semiconductors have been promising as gas sensors, getting them to achieve detection at low concentrations has remained a challenge for scientists. The University of Illinois team discovered that introducing nanopores between 50 and 700 nanometer in diameter to the surface of organic semiconductor thin films results in a drastically greater ability of the material to interact with volatile organic compounds.
From the study in journal Advanced Functional Materials:
Mechanistic investigations show that nanopores grant direct access to the highly reactive sites otherwise buried in the conductive channel of the transistor. The high reactivity of nanoporous organic field-effect transistors leads to unprecedented ultrasensitive, ultrafast, selective chemical sensing below the 1 ppb level on a hundred millisecond time scale, enabling a wide range of health and environmental applications.
Study in journal Advanced Functional Materials: Solution-Processed Nanoporous Organic Semiconductor Thin Films: Toward Health and Environmental Monitoring of Volatile Markers…