P1DH.13 - Si-doped α-MoO3 sensing nanoparticles for selective breath NH3 detection
- Event
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria - Chapter
- P-1 - Sensors for Diagnostics and Healthcare
- Author(s)
- M. Wied, A. Güntner, M. Righettoni, S. Pratsinis - Particle Technology Laboratory, ETH Zürich, Zurich (Switzerland)
- Pages
- 681 - 682
- DOI
- 10.5162/IMCS2018/P1DH.13
- ISBN
- 978-3-9816876-9-9
- Price
- free
Abstract
Ammonia is an important breath marker for non-invasive detection and monitoring of end-stage renal disease (ESRD). Here, a chemo-resistive gas sensor has been developed consisting of flame-made nanostructured α-MoO3 with ribbon-like and nanoparticle/needle-like morphologies. A key novelty is the thermal stabilization of α-MoO3 by Si-doping inhibiting sintering and crystal growth at the operational conditions of such sensors. In situ XRD analysis of the MoOx phase dynamics revealed an optimal annealing temperature of 450 °C for synthesis of highly nanocrystalline α-MoO3. For selective NH3 sensing, however, the optimum SiO2 content was 3 wt% and the operational temperature 400 °C. This sensor showed superior NH3 selectivity toward acetone, NO and CO, and accurately detected breath-relevant NH3 concentrations down to 400 ppb under 90% relative humidity (RH). As a result, a stable and inexpensive sensor for NH3 is presented which has the potential for further development toward a hand-held device for the early-stage diagnosis and monitoring of ESRD.