Controlling the overall geometry of plasmonic materials allows for tailoring their optical response and the effects that can be exploited to enhance the performance of a wide range of devices. This study demonstrates a simple method to control the size and distribution of gold (Au) nanoparticles grown on the surface of spaced titanium dioxide (TiO2) nanotubes by varying the deposition time of magnetron sputtering. While shorter depositions led to small and well-separated Au nanoparticles, longer depositions promoted the formation of quasi-continuous layers with small interparticle gaps. The optical spectra of Au/TiO2 nanotubes showed a region of strong absorption (200-550 nm) for all samples and a region of decreasing absorption with an increase of effective Au thickness (550-1100 nm). This behavior led to distinct trends in the Raman signal enhancement of the underlying TiO2 nanotubes depending on the excitation laser wavelength. Furthermore, the quasi-continuous layers formed at higher effective Au thicknesses promoted an amplification of the signal and an improvement in the detection limit of target molecules in surface-enhanced Raman scattering (SERS) experiments. These findings suggest a simple method for designing efficient devices with tailored light absorption and potential applications in detectors and other optical devices.

CEET Nanotechnology Centre VŠB Technical University of Ostrava 17 listopadu 2172 15 Ostrava Poruba 708 00 Czech Republic

Czech Advanced Technology and Research Institute Regional Centre of Advanced Technologies and Materials Department Palacký University Olomouc Šlechtitelů 27 Olomouc 78371 Czech Republic

Department of Chemistry and NIS Centre University of Turin Turin 10125 Italy

Department of Laser Physics and Photonics Faculty of Nuclear Sciences and Physical Engineering Czech Technical University Prague Břehová 7 11519 Prague Czech Republic

Department of Physical Chemistry Faculty of Science Palacký University 17 listopadu 1192 12 779 00 Olomouc Czech Republic

Micro and Nanostructured Materials Laboratory Department of Energy Politecnico di Milano Via Ponzio 34 3 Milano 20133 Italy

Zobrazit více v PubMed

Gwo S.Plasmonic Materials and Metastructures: Fundamentals, Current Status, and Perspectives; Elsevier: S.l., 2024.

Yu H.; Peng Y.; Yang Y.; Li Z.-Y. Plasmon-Enhanced Light–Matter Interactions and Applications. Npj Comput. Mater. 2019, 5 (1), 45.10.1038/s41524-019-0184-1. DOI

Hartland G. V. Optical Studies of Dynamics in Noble Metal Nanostructures. Chem. Rev. 2011, 111 (6), 3858–3887. 10.1021/cr1002547. PubMed DOI

UV–VIS and Photoluminescence Spectroscopy for Nanomaterials Characterization; Kumar C., Ed.; Springer Berlin Heidelberg: Berlin, Heidelberg, 2013.

Ding S.-Y.; Yi J.; Li J.-F.; Ren B.; Wu D.-Y.; Panneerselvam R.; Tian Z.-Q. Nanostructure-Based Plasmon-Enhanced Raman Spectroscopy for Surface Analysis of Materials. Nat. Rev. Mater. 2016, 1 (6), 1602110.1038/natrevmats.2016.21. DOI

Etchegoin P. G.; Le Ru E. C. A Perspective on Single Molecule SERS: Current Status and Future Challenges. Phys. Chem. Chem. Phys. 2008, 10 (40), 6079.10.1039/b809196j. PubMed DOI

Lee D.; Yoon S. Effect of Nanogap Curvature on SERS: A Finite-Difference Time-Domain Study. J. Phys. Chem. C 2016, 120 (37), 20642–20650. 10.1021/acs.jpcc.6b01453. DOI

Langer J.; Jimenez De Aberasturi D.; Aizpurua J.; Alvarez-Puebla R. A.; Auguié B.; Baumberg J. J.; Bazan G. C.; Bell S. E. J.; Boisen A.; Brolo A. G.; Choo J.; Cialla-May D.; Deckert V.; Fabris L.; Faulds K.; García De Abajo F. J.; Goodacre R.; Graham D.; Haes A. J.; Haynes C. L.; Huck C.; Itoh T.; Käll M.; Kneipp J.; Kotov N. A.; Kuang H.; Le Ru E. C.; Lee H. K.; Li J.-F.; Ling X. Y.; Maier S. A.; Mayerhöfer T.; Moskovits M.; Murakoshi K.; Nam J.-M.; Nie S.; Ozaki Y.; Pastoriza-Santos I.; Perez-Juste J.; Popp J.; Pucci A.; Reich S.; Ren B.; Schatz G. C.; Shegai T.; Schlücker S.; Tay L.-L.; Thomas K. G.; Tian Z.-Q.; Van Duyne R. P.; Vo-Dinh T.; Wang Y.; Willets K. A.; Xu C.; Xu H.; Xu Y.; Yamamoto Y. S.; Zhao B.; Liz-Marzán L. M. Present and Future of Surface-Enhanced Raman Scattering. ACS Nano 2020, 14 (1), 28–117. 10.1021/acsnano.9b04224. PubMed DOI PMC

Kim J.; Lee C.; Lee Y.; Lee J.; Park S.; Park S.; Nam J. Synthesis, Assembly, Optical Properties, and Sensing Applications of Plasmonic Gap Nanostructures. Adv. Mater. 2021, 33 (46), 200696610.1002/adma.202006966. PubMed DOI

Li C.; Man B.; Zhang C.; Yu J.; Liu G.; Tian M.; Li Z.; Zhao X.; Wang Z.; Cui W.; Wang T.; Wang J.; Lin X.; Xu S. Strong Plasmon Resonance Coupling in Micro-Extraction SERS Membrane for in Situ Detection of Molecular Aqueous Solutions. Sens. Actuators B Chem. 2024, 398, 13476710.1016/j.snb.2023.134767. DOI

Tabish T. A.; Dey P.; Mosca S.; Salimi M.; Palombo F.; Matousek P.; Stone N. Smart Gold Nanostructures for Light Mediated Cancer Theranostics: Combining Optical Diagnostics with Photothermal Therapy. Adv. Sci. 2020, 7 (15), 190344110.1002/advs.201903441. PubMed DOI PMC

Chen J.; Gong M.; Fan Y.; Feng J.; Han L.; Xin H. L.; Cao M.; Zhang Q.; Zhang D.; Lei D.; Yin Y. Collective Plasmon Coupling in Gold Nanoparticle Clusters for Highly Efficient Photothermal Therapy. ACS Nano 2022, 16 (1), 910–920. 10.1021/acsnano.1c08485. PubMed DOI

Hu Y.; Liu X.; Cai Z.; Zhang H.; Gao H.; He W.; Wu P.; Cai C.; Zhu J.-J.; Yan Z. Enhancing the Plasmon Resonance Absorption of Multibranched Gold Nanoparticles in the Near-Infrared Region for Photothermal Cancer Therapy: Theoretical Predictions and Experimental Verification. Chem. Mater. 2019, 31 (2), 471–482. 10.1021/acs.chemmater.8b04299. DOI

Gao M.; Zhu L.; Peh C. K.; Ho G. W. Solar Absorber Material and System Designs for Photothermal Water Vaporization towards Clean Water and Energy Production. Energy Environ. Sci. 2019, 12 (3), 841–864. 10.1039/C8EE01146J. DOI

Zhou L.; Tan Y.; Ji D.; Zhu B.; Zhang P.; Xu J.; Gan Q.; Yu Z.; Zhu J. Self-Assembly of Highly Efficient, Broadband Plasmonic Absorbers for Solar Steam Generation. Sci. Adv. 2016, 2 (4), e150122710.1126/sciadv.1501227. PubMed DOI PMC

Yu Y.; Xie Y.; Zhang P.; Zhang W.; Wang W.; Zhang S.; Ou Q.; Li W. Hot Spots Engineering by Dielectric Support for Enhanced Photocatalytic Redox Reactions. Nano Res. 2023, 16 (1), 239–247. 10.1007/s12274-022-4712-9. DOI

Liu D.; Xue C. Plasmonic Coupling Architectures for Enhanced Photocatalysis. Adv. Mater. 2021, 33 (46), 200573810.1002/adma.202005738. PubMed DOI

Duan H.; Hu H.; Kumar K.; Shen Z.; Yang J. K. W. Direct and Reliable Patterning of Plasmonic Nanostructures with Sub-10-Nm Gaps. ACS Nano 2011, 5 (9), 7593–7600. 10.1021/nn2025868. PubMed DOI

Chen Y.; Li H.; Chen J.; Li D.; Zhang M.; Yu G.; Jiang L.; Zong Y.; Dong B.; Zeng Z.; Wang Y.; Chi L. Self-Generating Nanogaps for Highly Effective Surface-Enhanced Raman Spectroscopy. Nano Res. 2022, 15 (4), 3496–3503. 10.1007/s12274-021-3924-8. DOI

Ding T.; Herrmann L. O.; De Nijs B.; Benz F.; Baumberg J. J. Self-Aligned Colloidal Lithography for Controllable and Tuneable Plasmonic Nanogaps. Small 2015, 11 (18), 2139–2143. 10.1002/smll.201402639. PubMed DOI PMC

Wang Z.; Horseman T.; Straub A. P.; Yip N. Y.; Li D.; Elimelech M.; Lin S. Pathways and Challenges for Efficient Solar-Thermal Desalination. Sci. Adv. 2019, 5 (7), eaax076310.1126/sciadv.aax0763. PubMed DOI PMC

Zhao F.; Guo Y.; Zhou X.; Shi W.; Yu G. Materials for Solar-Powered Water Evaporation. Nat. Rev. Mater. 2020, 5 (5), 388–401. 10.1038/s41578-020-0182-4. DOI

Zhu M.; Li Y.; Chen F.; Zhu X.; Dai J.; Li Y.; Yang Z.; Yan X.; Song J.; Wang Y.; Hitz E.; Luo W.; Lu M.; Yang B.; Hu L. Plasmonic Wood for High-Efficiency Solar Steam Generation. Adv. Energy Mater. 2018, 8 (4), 170102810.1002/aenm.201701028. DOI

Dzhagan V.; Mazur N.; Kapush O.; Skoryk M.; Pirko Y.; Yemets A.; Dzhahan V.; Shepeliavyi P.; Valakh M.; Yukhymchuk V. Self-Organized SERS Substrates with Efficient Analyte Enrichment in the Hot Spots. ACS Omega 2024, 9 (4), 4819–4830. 10.1021/acsomega.3c08393. PubMed DOI PMC

Riboni F.; Nguyen N. T.; So S.; Schmuki P. Aligned Metal Oxide Nanotube Arrays: Key-Aspects of Anodic TiO 2 Nanotube Formation and Properties. Nanoscale Horiz. 2016, 1 (6), 445–466. 10.1039/C6NH00054A. PubMed DOI

Ozkan S.; Mazare A.; Schmuki P. Critical Parameters and Factors in the Formation of Spaced TiO2 Nanotubes by Self-Organizing Anodization. Electrochim. Acta 2018, 268, 435–447. 10.1016/j.electacta.2018.02.120. DOI

Ozkan S.; Nguyen N. T.; Mazare A.; Schmuki P. Optimized Spacing between TiO 2 Nanotubes for Enhanced Light Harvesting and Charge Transfer. ChemElectroChem. 2018, 5 (21), 3183–3190. 10.1002/celc.201801136. DOI

Wawrzyniak J.; Grochowska K.; Karczewski J.; Kupracz P.; Ryl J.; Dołęga A.; Siuzdak K. The Geometry of Free-Standing Titania Nanotubes as a Critical Factor Controlling Their Optical and Photoelectrochemical Performance. Surf. Coat. Technol. 2020, 389, 12562810.1016/j.surfcoat.2020.125628. DOI

Zhou L.; Tan Y.; Wang J.; Xu W.; Yuan Y.; Cai W.; Zhu S.; Zhu J. 3D Self-Assembly of Aluminium Nanoparticles for Plasmon-Enhanced Solar Desalination. Nat. Photonics 2016, 10 (6), 393–398. 10.1038/nphoton.2016.75. DOI

Lee K.; Mazare A.; Schmuki P. One-Dimensional Titanium Dioxide Nanomaterials: Nanotubes. Chem. Rev. 2014, 114 (19), 9385–9454. 10.1021/cr500061m. PubMed DOI

Gudmundsson J. T. Physics and Technology of Magnetron Sputtering Discharges. Plasma Sources Sci. Technol. 2020, 29 (11), 11300110.1088/1361-6595/abb7bd. DOI

Ozkan S.; Nguyen N. T.; Hwang I.; Mazare A.; Schmuki P. Highly Conducting Spaced TiO 2 Nanotubes Enable Defined Conformal Coating with Nanocrystalline Nb 2 O 5 and High Performance Supercapacitor Applications. Small 2017, 13 (14), 160382110.1002/smll.201603821. PubMed DOI

Ozkan S.; Yoo J.; Nguyen N. T.; Mohajernia S.; Zazpe R.; Prikryl J.; Macak J. M.; Schmuki P. Spaced TiO 2 Nanotubes Enable Optimized Pt Atomic Layer Deposition for Efficient Photocatalytic H 2 Generation. ChemistryOpen 2018, 7 (10), 797–802. 10.1002/open.201800172. PubMed DOI PMC

Tesler A. B.; Altomare M.; Schmuki P. Morphology and Optical Properties of Highly Ordered TiO 2 Nanotubes Grown in NH 4 F/ o -H 3 PO 4 Electrolytes in View of Light-Harvesting and Catalytic Applications. ACS Appl. Nano Mater. 2020, 3 (11), 10646–10658. 10.1021/acsanm.0c01859. DOI

Xi J.-Q.; Schubert M. F.; Kim J. K.; Schubert E. F.; Chen M.; Lin S.-Y.; Liu W.; Smart J. A. Optical Thin-Film Materials with Low Refractive Index for Broadband Elimination of Fresnel Reflection. Nat. Photonics 2007, 1 (3), 176–179. 10.1038/nphoton.2007.26. DOI

Raut H. K.; Ganesh V. A.; Nair A. S.; Ramakrishna S. Anti-Reflective Coatings: A Critical, in-Depth Review. Energy Environ. Sci. 2011, 4 (10), 3779.10.1039/c1ee01297e. DOI

Zhang F.; Tang F.; Xu X.; Adam P.-M.; Martin J.; Plain J. Influence of Order-to-Disorder Transitions on the Optical Properties of the Aluminum Plasmonic Metasurface. Nanoscale 2020, 12 (45), 23173–23182. 10.1039/D0NR06334G. PubMed DOI

Palani S.; Kenison J. P.; Sabuncu S.; Huang T.; Civitci F.; Esener S.; Nan X. Multispectral Localized Surface Plasmon Resonance (msLSPR) Reveals and Overcomes Spectral and Sensing Heterogeneities of Single Gold Nanoparticles. ACS Nano 2023, 17 (3), 2266–2278. 10.1021/acsnano.2c08702. PubMed DOI PMC

Henrotte O.; Santiago E. Y.; Movsesyan A.; Mascaretti L.; Afshar M.; Minguzzi A.; Vertova A.; Wang Z. M.; Zboril R.; Kment S.; Govorov A. O.; Naldoni A. Local Photochemical Nanoscopy of Hot-Carrier-Driven Catalytic Reactions Using Plasmonic Nanosystems. ACS Nano 2023, 17 (12), 11427–11438. 10.1021/acsnano.3c01009. PubMed DOI

Reineck P.; Brick D.; Mulvaney P.; Bach U. Plasmonic Hot Electron Solar Cells: The Effect of Nanoparticle Size on Quantum Efficiency. J. Phys. Chem. Lett. 2016, 7 (20), 4137–4141. 10.1021/acs.jpclett.6b01884. PubMed DOI

Kim H. J.; Lee S. H.; Upadhye A. A.; Ro I.; Tejedor-Tejedor M. I.; Anderson M. A.; Kim W. B.; Huber G. W. Plasmon-Enhanced Photoelectrochemical Water Splitting with Size-Controllable Gold Nanodot Arrays. ACS Nano 2014, 8 (10), 10756–10765. 10.1021/nn504484u. PubMed DOI

Balachandran U.; Eror N. G. Raman Spectra of Titanium Dioxide. J. Solid State Chem. 1982, 42 (3), 276–282. 10.1016/0022-4596(82)90006-8. DOI

Ohsaka T.; Izumi F.; Fujiki Y. Raman Spectrum of Anatase, TiO 2. J. Raman Spectrosc. 1978, 7 (6), 321–324. 10.1002/jrs.1250070606. DOI

Chih Lin M.; Nien L.-W.; Chen C.-H.; Lee C.-W.; Chen M.-J. Surface Enhanced Raman Scattering and Localized Surface Plasmon Resonance of Nanoscale Ultrathin Films Prepared by Atomic Layer Deposition. Appl. Phys. Lett. 2012, 101 (2), 02311210.1063/1.4729411. DOI

Kashyap K. K.; Choudhuri B.; Chinnamuthu P. Enhanced Optical and Electrical Properties of Metallic Surface Plasmon Sensitized TiO 2 Nanowires. IEEE Trans. Nanotechnol. 2020, 19, 519–526. 10.1109/TNANO.2020.3004876. DOI

Stroyuk O. L.; Dzhagan V. M.; Kozytskiy A. V.; Breslavskiy A. Ya.; Kuchmiy S. Ya.; Villabona A.; Zahn D. R. T. Nanocrystalline TiO2/Au Films: Photocatalytic Deposition of Gold Nanocrystals and Plasmonic Enhancement of Raman Scattering from Titania. Mater. Sci. Semicond. Process. 2015, 37, 3–8. 10.1016/j.mssp.2014.12.033. DOI

Virga A.; Rivolo P.; Frascella F.; Angelini A.; Descrovi E.; Geobaldo F.; Giorgis F. Silver Nanoparticles on Porous Silicon: Approaching Single Molecule Detection in Resonant SERS Regime. J. Phys. Chem. C 2013, 117 (39), 20139–20145. 10.1021/jp405117p. DOI

Coluccio M. L.; Das G.; Mecarini F.; Gentile F.; Pujia A.; Bava L.; Tallerico R.; Candeloro P.; Liberale C.; De Angelis F.; Di Fabrizio E. Silver-Based Surface Enhanced Raman Scattering (SERS) Substrate Fabrication Using Nanolithography and Site Selective Electroless Deposition. Microelectron. Eng. 2009, 86 (4–6), 1085–1088. 10.1016/j.mee.2008.12.061. DOI

Torrell M.; Kabir R.; Cunha L.; Vasilevskiy M. I.; Vaz F.; Cavaleiro A.; Alves E.; Barradas N. P. Tuning of the Surface Plasmon Resonance in TiO2/Au Thin Films Grown by Magnetron Sputtering: The Effect of Thermal Annealing. J. Appl. Phys. 2011, 109 (7), 07431010.1063/1.3565066. DOI

Brognara A.; Mohamad Ali Nasri I. F.; Bricchi B. R.; Li Bassi A.; Gauchotte-Lindsay C.; Ghidelli M.; Lidgi-Guigui N. Highly Sensitive Detection of Estradiol by a SERS Sensor Based on TiO 2 Covered with Gold Nanoparticles. Beilstein J. Nanotechnol. 2020, 11, 1026–1035. 10.3762/bjnano.11.87. PubMed DOI PMC