Rethinking Biosensors for Exhaled Breath: A Perspective on Gas and Condensate Detection

Analysing the exhaled breath and its condensate (EBC) can offer a simple, non-invasive way to track physiological states through volatile and non-volatile biomarkers detection. Biosensors, leveraging biological recognition elements, as enzymes, promise selective recognition of these analytes and could overcome the limitations of traditional gas sensors. However, transitioning from liquid to gas-phase sensing presents significant challenges, including enzyme instability, weak signals, and lack of sampling standardization. On the other hand, EBC biosensors, while more compatible with biological elements, face limitations due to the low analyte concentrations and variable sample quality. This perspective looks at the current progress in gas-phase and EBC-based biosensors, highlighting the most promising emerging technologies and key limitations. With the right advances, these tools could facilitate the implementation of fast and non-invasive testing in routine healthcare.