GENERAL SEMINAR: Dr. Cosmin Farcău, National Institute for Research and Development of Isotopic and Molecular Technologies, Romania
Abstract:
Advances in nanofabrication enable plasmonic/photonic architectures with tunable optical responses, offering powerful platforms for enhanced spectroscopies, sensing, and light-emission control. In this talk, I will present our recent results on large-area plasmonic nanostructures obtained through colloidal self-assembly and colloidal lithography, combined with plasma etching, electrodeposition, and physical vapor deposition. The resulting architectures include compact films of shape-controlled nanoparticles, metal-coated microsphere lattices, and nanovoid arrays. Control over sphere size, interparticle spacing, and film thickness allows precise tuning of surface plasmon resonances and field localization. FDTD simulations, supported by reflectance and transmittance measurements, reveal the interplay between localized and propagating plasmon modes, which we correlate with the enhancements observed in surface-enhanced Raman scattering (SERS) and fluorescence (SEF). These substrates enable sensitive and reproducible detection of challenging analytes, including pesticides, and can be integrated into electrochemical and microfluidic devices for in-flow sensing. Overall, colloidal nanofabrication emerges as a scalable, low-cost route to tunable plasmonic platforms, providing insight into nanoscale light-matter interactions and pathways toward practical sensing applications.
Biography.
Cosmin Farcău is a Senior Researcher at the National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), where he leads the NanoPhotoniX team, and at the Babeș-Bolyai University in Cluj-Napoca, Romania. He received his PhD in Physics from Babeș-Bolyai University in 2008 and carried out postdoctoral research at CEMES and LPCNO in Toulouse, France. His research focuses on the self-assembly of nano- and microparticles, the fabrication of plasmonic nanostructures, and the study of optical interactions in nanostructured films. His interests also include plasmon-enhanced molecular optical processes (such as fluorescence and Raman scattering) and the integration of these materials and effects into nanophotonic devices for sensing and light emission. He is the author of over 90 scientific publications (over 2200 citations, h-index 27) and serves on the editorial board of Discover Nano. More information is available at http://en.itim-cj.ro/portfolio/farcau-cosmin/.
References.
- D. Cuibus, I. Cârdan, N. Tosa, A. M. M. Gherman, C. Farcău, Self-Assembly Route Controls Nanoscale Structural Order and SERS Sensing Performance in Ag Film-over-Nanosphere Plasmonic Substrates, ACS Appl. Nano Mat. 2026, 9, 14177.
- I. Cardan, A. Falamaș, D. Cuibus, V. Zani, R. Signorini, R. Pilot, C. Farcău, Quasi-3D Sculpted Gold Film over Nanospheres (AuFoN) for Enhanced SERS Detection of Emerging Pollutants, Microchem. J. 2026, 228, 118905.
- A. Falamaș, A.M.M. Gherman, R. Vallée, C. Farcău, Metasurface Engineering with Tantalum Pentoxide-Coated Microspheres: Tailoring Optical Resonances and Enhancing Local Density of States, ACS Appl. Opt. Mat. 2026, 4, 1769.
- I. Cardan, V. Zani, A.M.M. Gherman, R. Signorini, R. Pilot, C. Farcau, From molecules to nanoplastics SERS detection: new insights into the role of analyte on the plasmonic substrate design, Nanoscale 2025, 17, 25680.
- I. Marica, M. Ştefan, S. Boca, A. Falamaș, C. Farcău, A simple approach for coffee-ring suppression yielding homogeneous drying patterns of ZnO and TiO2 nanoparticles, J. Colloid Interface Sci. 2023, 635, 117.
- N. Nechita, C. Farcau, Tuning plasmons of metal-coated microsphere arrays towards optimized surface-enhanced spectroscopy, Opt. Express 2021, 29, 42238.