In this paper, an innovative device with gas remote-sensing capability is proposed, which is based on the interaction between magnetic nanoparticles and gases associated with exhaled breath biomarkers that can have a metabolic origin. Magnetite (Fe₃O₄) nanoparticles of around 30 nm have been used. The gas molecules adsorbed on surface modulate the magnetization of the nanoparticles and magnetostatic surface spin waves (MSSW) propagated on an yttrium iron garnet (YIG) thin film are used to detect this modulation by the induced frequency shift. The optimization of the remote gas sensor has been carried out through simulations of a magnetic model. Simulations show the feasibility of developing a high-performance remote sensor by encapsulating the nanostructures in a polytetrafluoroethylene (PTFE) tube and detecting part per million changes in their magnetization. The results show the possibility of developing new, inexpensive, reusable, contactless magnetic gas sensors employing spin waves as transductor. The developed sensor shows a high sensitivity and selectivity to concentrations as low as 50 ppm of different breath biomarkers.
Acknowledgements
The authors acknowledge the Spanish Ministry of Science and Innovation for financing the projects RETOS RTI2018-095856-B, RTI2018-095856-B-C22 (AEI/FEDER), RTI2018-095856-B-C21 (AEI/FEDER), PID2021-123112OB-C21 (AEI/FEDER), PDC2022-133039-I00 (AEI/FEDER), Comunidad de Madrid (NANOMAGCOST-CM S2018/NMT-4321 and COST Action CA21101. J.D.A received funding from Next Generation EU, Ministerio de Trabajo y Economía, Comunidad de Madrid, Spain, Programa Investigo from grant 96-UCM-INV. D. M. acknowledges financial support from the Spanish Ministry of Science and Innovation (MCI) through the Ramón y Cajal grant RYC2021-031166-I. A. P. acknowledges funding from grant PRE2019-0875001234 (MCI).
