Image: Bezdek Group / ETH Zurich
Oxygen plays a crucial role in both life and various chemical processes, making its accurate measurement vital across numerous industrial and medical applications. Recent advancements in this field are emerging from research efforts at ETH Zurich, where a team led by Professor Máté Bezdek has developed a novel, light-activated high-performance oxygen sensor. This sensor has been designed to operate efficiently in environmental monitoring, a sector increasingly reliant on accurate oxygen measurements.
In a study published in the journal Advanced Science, Bezdek and his colleagues introduce a sensor capable of precisely detecting oxygen in complex gas mixtures while maintaining the necessary properties for field deployment. According to Bezdek, “In contrast to other gases, oxygen hinders this charge transfer in the activated sensor, which changes its resistance,” illustrating the innovative mechanism employed in the sensor’s reaction. This is achieved through a photosensitiser that, when exposed to green light, facilitates electron transfer to a composite material made of titanium dioxide and carbon nanotubes, activating the material for enhanced oxygen sensitivity.
One of the major challenges with existing oxygen measurement technologies has been their size, power consumption, and cost, which often render them impractical for mobile applications or continuous outdoor use. The new sensor addresses these issues, boasting sensitivity that allows it to detect oxygen amidst a million gas particles, while remaining resistant to humidity and other interfering gases. Lionel Wettstein, a PhD student and first author of the study, notes that conventional methods typically sacrifice high sensitivity for other performance criteria, which this new technology aims to balance effectively.
Bezdek’s team is actively seeking industrial partnerships to advance the development of their patented sensor technology. The estimated annual market volume for durable and reliable sensors specifically measuring oxygen in gas mixtures stands at approximately 1.4 billion US dollars. Furthermore, the researchers are exploring the potential of their sensor material for detecting other environmentally significant gases, particularly nitrogen-based pollutants which are known to contribute to over-fertilisation and subsequent pollution in agricultural contexts. Bezdek emphasises the need for “sensors that enable precise fertilisation of fields” to mitigate agriculture’s ecological footprint.
The research team’s sensor relies on a modular design that lends itself to further modifications. By altering the chemical composition of the sensor material, the group hopes to extend its capabilities to include various target molecules in the environmental space.
With practical applications ranging from analysing vehicle exhaust to monitoring ecosystems—such as lakes, rivers, and soils—the introduction of this sensor could provide effective tools for real-time environmental assessments. Wettstein points out that “the oxygen content in these ecosystems is an important indicator of ecological health,” signalling the sensor’s potential significance in environmental preservation efforts.
This extensive research indicates a promising step forward in the realm of oxygen detection, with implications that could enhance our understanding of environmental health and support sustainable technological advancements.
