Selective monitoring of breath isoprene by a portable detector during exercise and at rest

Isoprene has received widespread attention in breath research because of its potential to serve as a sensitive and non-invasive biomarker for the detection monitoring several metabolic effects. To date, activity on isoprene focused mass spectrometry-based measurement techniques, which are not portable require skilled operators. Here, we show, first time our knowledge, selective exhaled (148 samples, 60–1250 parts-per-billion, ppb) with an inexpensive, user-friendly compact filter–sensor device. This detector is based previously developed concept comprising sorption filter activated alumina that removes hydrophilic volatiles ahead micro gas sensor consisting chemoresistive Si-doped WO3 nanoparticles quantify down few ppb concentrations. When tested humans during exercise at rest, accurately followed dynamics linear (Pearson’s coefficient 0.89) correlation proton transfer reaction spectrometry measurements. Most importantly, output from device interfered by high variable concentrations other volatile compounds, specifically acetone, ethanol methanol. can be readily applied online physical activity.