{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T22:29:26Z","timestamp":1768256966917,"version":"3.49.0"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2019,5,25]],"date-time":"2019-05-25T00:00:00Z","timestamp":1558742400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/FIS\/04650\/2019"],"award-info":[{"award-number":["UID\/FIS\/04650\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/FIS-NAN\/1154\/2014"],"award-info":[{"award-number":["PTDC\/FIS-NAN\/1154\/2014"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/FIS-MAC\/32299\/2017"],"award-info":[{"award-number":["PTDC\/FIS-MAC\/32299\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/137076\/2018"],"award-info":[{"award-number":["SFRH\/BD\/137076\/2018"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BPD\/117010\/2016"],"award-info":[{"award-number":["SFRH\/BPD\/117010\/2016"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/118684\/2016"],"award-info":[{"award-number":["SFRH\/BD\/118684\/2016"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-016902"],"award-info":[{"award-number":["POCI-01-0145-FEDER-016902"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-032299"],"award-info":[{"award-number":["POCI-01-0145-FEDER-032299"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Coatings"],"abstract":"<jats:p>Magnetron sputtered nanocomposite thin films composed of monometallic Au and Ag, and bimetallic Au-Ag nanoparticles, dispersed in a CuO matrix, were prepared, characterized, and tested, which aimed to find suitable nano-plasmonic platforms capable of detecting the presence of gas molecules. The Localized Surface Plasmon Resonance phenomenon, LSPR, induced by the morphological changes of the nanoparticles (size, shape, and distribution), and promoted by the thermal annealing of the films, was used to tailor the sensitivity to the gas molecules. Results showed that the monometallic films, Au:CuO and Ag:CuO, present LSPR bands at ~719 and ~393 nm, respectively, while the bimetallic Au-Ag:CuO film has two LSPR bands, which suggests the presence of two noble metal phases. Through transmittance-LSPR measurements, the bimetallic films revealed to have the highest sensitivity to the refractive index changes, as well as high signal-to-noise ratios, respond consistently to the presence of a test gas.<\/jats:p>","DOI":"10.3390\/coatings9050337","type":"journal-article","created":{"date-parts":[[2019,5,26]],"date-time":"2019-05-26T23:07:27Z","timestamp":1558912047000},"page":"337","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Gas Sensing with Nanoplasmonic Thin Films Composed of Nanoparticles (Au, Ag) Dispersed in a CuO Matrix"],"prefix":"10.3390","volume":"9","author":[{"given":"Manuela","family":"Proen\u00e7a","sequence":"first","affiliation":[{"name":"Centro de F\u00edsica da Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3291-0925","authenticated-orcid":false,"given":"Marco S.","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Centro de F\u00edsica da Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7421-6902","authenticated-orcid":false,"given":"Joel","family":"Borges","sequence":"additional","affiliation":[{"name":"Centro de F\u00edsica da Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Filipe","family":"Vaz","sequence":"additional","affiliation":[{"name":"Centro de F\u00edsica da Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/j.surfcoat.2017.08.033","article-title":"Development of Au\/CuO nanoplasmonic thin films for sensing applications","volume":"343","author":"Borges","year":"2018","journal-title":"Surf. Coat. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1088\/1361-6528\/ab068e","article-title":"Nanoplasmonic response of porous Au-TiO2 thin films prepared by oblique angle deposition","volume":"30","author":"Rodrigues","year":"2019","journal-title":"Nanotechnology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"205102","DOI":"10.1088\/1361-6463\/aabc49","article-title":"Thin films of Ag-Au nanoparticles dispersed in TiO2: Influence of composition and microstructure on the LSPR and SERS responses","volume":"51","author":"Borges","year":"2018","journal-title":"J. Phys. D. Appl. Phys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.tsf.2015.03.024","article-title":"Microstructural evolution of Au\/TiO2 nanocomposite films: The influence of Au concentration and thermal annealing","volume":"580","author":"Borges","year":"2015","journal-title":"Thin Solid Films"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"16931","DOI":"10.1021\/acs.jpcc.6b03684","article-title":"Broadband optical absorption caused by the plasmonic response of coalesced Au nanoparticles embedded in a TiO2 matrix","volume":"120","author":"Borges","year":"2016","journal-title":"J. Phys. Chem. C"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4797","DOI":"10.1021\/cr0680282","article-title":"Interparticle coupling effect on the surface plasmon resonance of gold nanoparticles: From theory to applications","volume":"107","author":"Ghosh","year":"2007","journal-title":"Chem. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1685","DOI":"10.1002\/adma.200400271","article-title":"Exploitation of localized surface plasmon resonance","volume":"16","author":"Hutter","year":"2004","journal-title":"Adv. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"045415","DOI":"10.1103\/PhysRevB.86.045415","article-title":"Advanced optical effective medium modeling for a single layer of polydisperse ellipsoidal nanoparticles embedded in a homogeneous dielectric medium: Surface plasmon resonances","volume":"86","author":"Toudert","year":"2012","journal-title":"Phys. Rev. B"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1007\/s11468-008-9070-2","article-title":"Dispersion and damping of gold surface plasmon","volume":"3","author":"Politano","year":"2008","journal-title":"Plasmonics"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1088\/0034-4885\/70\/1\/R01","article-title":"Theory of surface plasmons and surface-plasmon polaritons","volume":"70","author":"Pitarke","year":"2007","journal-title":"Rep. Prog. Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1038\/nature10904","article-title":"Quantum plasmon resonances of individual metallic nanoparticles","volume":"483","author":"Scholl","year":"2012","journal-title":"Nature"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.cplett.2011.02.059","article-title":"Fullerene-like CSx: A first-principles study of synthetic growth","volume":"506","author":"Goyenola","year":"2011","journal-title":"Chem. Phys. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"554","DOI":"10.1179\/1743294415Y.0000000085","article-title":"Functional behaviour of TiO2 films doped with noble metals","volume":"32","author":"Rodrigues","year":"2016","journal-title":"Surf. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"6536","DOI":"10.1016\/j.apsusc.2010.04.043","article-title":"Functional and optical properties of Au:TiO2 nanocomposite films: The influence of thermal annealing","volume":"256","author":"Torrell","year":"2010","journal-title":"Appl. Surf. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.bios.2018.05.047","article-title":"Electroactive Au@Ag nanoparticles driven electrochemical sensor for endogenous H2S detection","volume":"117","author":"Zhao","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.apsusc.2014.02.050","article-title":"Synthesis and biosensor application of Ag@Au bimetallic nanoparticles based on localized surface plasmon resonance","volume":"301","author":"Ghodselahi","year":"2014","journal-title":"Appl. Surf. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2790","DOI":"10.1007\/s11051-014-2790-7","article-title":"Evolution of the surface plasmon resonance of Au:TiO2 nanocomposite thin films with annealing temperature","volume":"16","author":"Borges","year":"2014","journal-title":"J. Nanopart. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.aca.2011.08.020","article-title":"Localized surface plasmon resonance: Nanostructures, bioassays and biosensing\u2014A review","volume":"706","author":"Petryayeva","year":"2011","journal-title":"Anal. Chim. Acta"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1016\/j.mssp.2018.03.025","article-title":"Bidimensional ordered plasmonic nanoarrays for nonlinear optics, nanophotonics and biosensing applications","volume":"92","author":"Cesca","year":"2019","journal-title":"Mater. Sci. Semicond. Process."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.colcom.2018.04.001","article-title":"Polymer stabilized bimetallic alloy nanoparticles: Synthesis and catalytic application","volume":"24","author":"Dwivedi","year":"2018","journal-title":"Colloid Interface Sci. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/j.jqsrt.2015.07.024","article-title":"Au@Ag core\/shell cuboids and dumbbells: Optical properties and SERS response","volume":"167","author":"Khlebtsov","year":"2015","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.jallcom.2009.06.201","article-title":"The effect of Au\/Ag ratios on surface composition and optical properties of co-sputtered alloy nanoparticles in Au-Ag:SiO2 thin films","volume":"486","author":"Sangpour","year":"2009","journal-title":"J. Alloy. Compd."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"7438","DOI":"10.1016\/j.apsusc.2007.03.050","article-title":"rf reactive co-sputtered Au-Ag alloy nanoparticles in SiO2 thin films","volume":"253","author":"Sangpour","year":"2007","journal-title":"Appl. Surf. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1050","DOI":"10.1016\/j.apsusc.2016.08.034","article-title":"Anchoring of Ag-Au alloy nanoparticles on reduced graphene oxide sheets for the reduction of 4-nitrophenol","volume":"389","author":"Hareesh","year":"2016","journal-title":"Appl. Surf. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1134\/S0036024416010301","article-title":"Synthesis of large uniform gold and core\u2013shell gold\u2013silver nanoparticles: Effect of temperature control","volume":"90","author":"Tiunov","year":"2016","journal-title":"Russ. J. Phys. Chem. A"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"17143","DOI":"10.1021\/la303513x","article-title":"AgAu bimetallic janus nanoparticles and their electrocatalytic activity for oxygen reduction in alkaline media","volume":"28","author":"Song","year":"2012","journal-title":"Langmuir"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.physb.2006.12.011","article-title":"Plasmon absorption in nanospheres: A comparison of sodium, potassium, aluminium, silver and gold","volume":"394","author":"Blaber","year":"2007","journal-title":"Phys. B Condens. Matter"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/j.apsusc.2019.04.085","article-title":"Nanocomposite thin films based on Au-Ag nanoparticles embedded in a CuO matrix for localized surface plasmon resonance sensing","volume":"484","author":"Borges","year":"2019","journal-title":"Appl. Surf. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"012001","DOI":"10.7567\/APEX.11.012001","article-title":"UV plasmonic device for sensing ethanol and acetone","volume":"11","author":"Honda","year":"2018","journal-title":"Appl. Phys. Express"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"8042","DOI":"10.1021\/ac102127p","article-title":"Metal-organic framework thin film for enhanced localized surface Plasmon resonance gas sensing","volume":"82","author":"Kreno","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1447","DOI":"10.2217\/nnm.11.117","article-title":"Advances in localized surface plasmon resonance spectroscopy biosensing","volume":"6","author":"Sagle","year":"2011","journal-title":"Nanomedicine"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"172","DOI":"10.3390\/bios4020172","article-title":"Localized surface plasmon resonance as a biosensing platform for developing countries","volume":"4","author":"Hammond","year":"2014","journal-title":"Biosensors"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"6961","DOI":"10.1021\/jp036261n","article-title":"Nanoscale optical biosensor: Short range distance dependence of the localized surface plasmon resonance of noble metal nanoparticles","volume":"108","author":"Haes","year":"2004","journal-title":"J. Phys. Chem. B"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"17358","DOI":"10.1021\/ja1074272","article-title":"Van gas sensing with high-resolution localized surface plasmon resonance spectroscopy","volume":"132","author":"Bingham","year":"2010","journal-title":"J. Am. Chem. Soc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"5381","DOI":"10.1021\/acs.langmuir.8b00040","article-title":"Water adsorption by a sensitive calibrated gold plasmonic nanosensor","volume":"34","author":"Demirdjian","year":"2018","journal-title":"Langmuir"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"11331","DOI":"10.1038\/ncomms11331","article-title":"Dispersion and shape engineered plasmonic nanosensors","volume":"7","author":"Jeong","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"7399","DOI":"10.1021\/ac500883x","article-title":"Curvature of the localized surface plasmon resonance peak","volume":"86","author":"Chen","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"8227","DOI":"10.1021\/jp409954s","article-title":"Critical issues in localized plasmon sensing","volume":"118","author":"Kedem","year":"2014","journal-title":"J. Phys. Chem. C"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"5636","DOI":"10.1021\/la971228b","article-title":"Quantitative interpretation of the response of surface plasmon resonance sensors to adsorbed films","volume":"14","author":"Jung","year":"1998","journal-title":"Langmuir"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"244905","DOI":"10.1063\/1.4812584","article-title":"Structural and optical properties of Ag-doped copper oxide thin films on polyethylene napthalate substrate prepared by low temperature microwave annealing","volume":"113","author":"Das","year":"2013","journal-title":"J. Appl. Phys."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"20069","DOI":"10.3390\/s150820069","article-title":"Gas-sensing performance of M-doped CuO-based thin films working at different temperatures upon exposure to propane","volume":"15","author":"Rydosz","year":"2015","journal-title":"Sensors"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1002\/ppap.201500063","article-title":"Ag:TiN-coated polyurethane for dry biopotential electrodes: From polymer plasma interface activation to the first EEG measurements","volume":"13","author":"Pedrosa","year":"2016","journal-title":"Plasma Process. Polym."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1875","DOI":"10.1016\/j.nimb.2007.10.044","article-title":"Advanced physics and algorithms in the IBA DataFurnace","volume":"266","author":"Barradas","year":"2008","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. B"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1007\/s11595-015-1106-9","article-title":"Effects of annealing temperature on the properties of copper films prepared by magnetron sputtering","volume":"30","author":"Liu","year":"2015","journal-title":"J. Wuhan Univ. Technol. Mater. Sci. Ed."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.tsf.2004.10.043","article-title":"Reactive magnetron sputtering of copper, silver, and gold","volume":"478","author":"Pierson","year":"2005","journal-title":"Thin Solid Films"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3949","DOI":"10.1016\/j.apsusc.2007.12.019","article-title":"Effect of post-annealing on the properties of copper oxide thin films obtained from the oxidation of evaporated metallic copper","volume":"254","author":"Figueiredo","year":"2008","journal-title":"Appl. Surf. Sci."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"9008","DOI":"10.1021\/jp101248h","article-title":"Monitoring of the plasmon resonance of gold nanoparticles in Au\/TiO2 catalyst under oxidative and reducing atmospheres","volume":"114","author":"Borensztein","year":"2010","journal-title":"J. Phys. Chem. C"}],"container-title":["Coatings"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6412\/9\/5\/337\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:55:03Z","timestamp":1760187303000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6412\/9\/5\/337"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,5,25]]},"references-count":47,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2019,5]]}},"alternative-id":["coatings9050337"],"URL":"https:\/\/doi.org\/10.3390\/coatings9050337","relation":{},"ISSN":["2079-6412"],"issn-type":[{"value":"2079-6412","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,5,25]]}}}