| Summary: | 298 Fabrication and Characterization of End Grafted Polymer Layers as a Platform for HeterogeneousPlasmonic Structures Sami PEKDEMİR, Özge CANPOLAT, M. Serdar ÖNSES Erciyes University, Faculty of Engineering, Department of Material Science and Engineering, Kayseri, Turkey samipekdemir@erciyes.edu.tr, ozgecanpolat38@gmail.com, onses@erciyes.edu.tr Metallic structures at the nanometer scale show great promise both for fundamental scientific studies and practical technological applications. The optical properties of metallic nanoparticles (NPs) are determined by localized surface plasmonic resonances (LSPR)[1]. The frequency, intensity and quality of LSPR for an individual metallic nanostructure are dependent on the size, geometry and composition of the particle, and the refractive index of the local medium[2]. Moreover, the LSPR of nanoscale metals can be modulated with the neighbor metallic NPs that are placed in close- proximity, resulting in plasmonic coupling in between the individual NPs [3-5]. A good example to utilization of such plasmonic coupling involves surface- enhanced Raman spectroscopy (SERS) where the strong localization of electric fields in gaps between the individual metallic NPs significantly increase the intensity of Raman scattering of analyte molecules [6]. This allows of detection of low concentrations of molecules in Raman spectroscopy. The controllable and close placement of metallic NPs of varying composition is important for achieving unique plasmonic properties and heterogeneous structures. This study involved fabrication of substrates functionalized with two different polymer brushes for immobilization and assembly of colloidal gold and silver NPs with the objective of generating plasmonic heterogeneous structures. In this direction, a binary brushes were fabricated by sequential grafting of end-functional poly(2-vinyl pyridine) and poly(ethylene glycol) to the surface of silicon and glass substrates. Colloidal gold and silver NPs with different sizes and geometries were then selectively immobilized on these substrates functionalized with binary brushes. Finally, the optical and structural properties of gold-silver heterogeneous structures were characterized with ultraviolet–visible spectroscopy, SERS and electron microscopy. Keywords Multifunctional nanostructures, polymer thin films, metallic nanoparticles, gold-silver heterogeneous structures Acknowledgments This study was supported by Erciyes University Scientific Research Projects Unit with project code FYL-2017-7016. References [1] Lal, S.; Link, S.; Halas, N. J. Nat. Photonics 2007, 1, 641–648. [2] Shore, M. S.; Wang, J.; Johnston-Peck, A. C.; Oldenburg, A. L.; Tracy, J. B. Small 2011, 7, 230–234. [3] Peng, Z.; Yang, H. Nano Today 2009, 4, 143–164 [4] Rechberger, W.; Hohenau, A.; Leitner, A.; Krenn, J. R.; Lamprecht, B.; Aussenegg, F. R. Opt. Commun. 2003, 220, 137–141. [5] Jain, P. K.; Huang, W. Y.; El-Sayed, M. A. Nano Lett. 2007, 7, 2080–2088. [6] Xia Y, Halas NJ (2005) MRS Bull 30:338–348
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