{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:58:04Z","timestamp":1760057884524,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,2,26]],"date-time":"2025-02-26T00:00:00Z","timestamp":1740528000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union (EU)","award":["UIDP\/50014\/2020"],"award-info":[{"award-number":["UIDP\/50014\/2020"]}]},{"name":"National Funds","award":["UIDP\/50014\/2020"],"award-info":[{"award-number":["UIDP\/50014\/2020"]}]},{"name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","award":["UIDP\/50014\/2020"],"award-info":[{"award-number":["UIDP\/50014\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Magneto-optic surface plasmon resonances (MOSPRs) rely on the interaction of magnetic fields with surface plasmon polaritons (SPP) to modulate plasmonic bands with magnetic fields and enhance magneto-optical activity. In the present work, a study on the magnetoplasmonic behavior of Ag\/Fe bilayers is carried out by VIS-NIR spectroscopy and backed with SQUID measurements, determining the thickness-dependent magnetization of thin-film samples. The MOSPR sensing properties of Ag\/Fe planar bilayers are simulated using Berreman\u2019s matrix formalism, from which an optimized structure composed of 15 nm of Ag and 12.5 nm of Fe is obtained. The selected structure is fabricated and characterized for refractive index (RI) sensitivity, reaching 4946 RIU\u22121 and returning an effective enhancement of refractometric sensitivity after magneto-optical modulation. A new optimized and cobalt-free magnetoplasmonic Ag\/Fe bilayer structure is studied, fabricated, and characterized for the first time towards refractometric sensing, to the best of our knowledge. This configuration exhibits potential for enhancing refractometric sensitivity via magneto-optical modulation, thus paving the way towards a simpler, more accessible, and safe type of RI sensor with potential applications in chemical sensors and biosensors.<\/jats:p>","DOI":"10.3390\/s25051419","type":"journal-article","created":{"date-parts":[[2025,2,26]],"date-time":"2025-02-26T06:15:33Z","timestamp":1740550533000},"page":"1419","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Optimization of Magnetoplasmonic Behavior in Ag\/Fe Bilayer Nanostructures Towards Refractometric Sensing"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3633-7628","authenticated-orcid":false,"given":"Jo\u00e3o Pedro Miranda","family":"Carvalho","sequence":"first","affiliation":[{"name":"Centre for Applied Photonics, INESC TEC\u2014Institute for Systems and Computer Engineering, Technology and Science, 4150-179 Porto, Portugal"},{"name":"Department of Physics and Astronomy, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3952-2311","authenticated-orcid":false,"given":"Bernardo S.","family":"Dias","sequence":"additional","affiliation":[{"name":"Van der Waals-Zeeman Institute for Experimental Physics, Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6205-9479","authenticated-orcid":false,"given":"Lu\u00eds C. C.","family":"Coelho","sequence":"additional","affiliation":[{"name":"Centre for Applied Photonics, INESC TEC\u2014Institute for Systems and Computer Engineering, Technology and Science, 4150-179 Porto, Portugal"},{"name":"Department of Physics and Astronomy, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3810-5943","authenticated-orcid":false,"given":"Jos\u00e9 M. M. M. de","family":"Almeida","sequence":"additional","affiliation":[{"name":"Centre for Applied Photonics, INESC TEC\u2014Institute for Systems and Computer Engineering, Technology and Science, 4150-179 Porto, Portugal"},{"name":"School of Science and Technology, University of Tr\u00e1s-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Maier, S.A. (2007). Plasmonics: Fundamentals and Applications, Springer. 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