Nanoplasmonics and Surface Enhanced Spectroscopy

Layer-by-Layer Assembly of Silver Nanoparticles on Diatom Strips for Surface-enhanced Raman Scattering

Ayse Mine Saridag1, Ebru Aktas1, Mehmet Kahraman1*

1 Department o Chemistry, Gaziantep University, Gaziantep, Turkey
E-mail: ayseminesaridag@gmail.com

Surface-enhanced Raman Scattering (SERS) is an emerging analytical technique used for characterization of biological and non-biological structures [1,2]. Plasmonic properties of nanostructures are main factors influencing SERS performance. Thus, fabrication of plasmonic nanostructures having different plasmonic properties is significant research interest. Recently, guided-mode resonances (GMRs) in diatoms have significant attention due to their potential contribution to SERS enhancement [3-5]. Furthermore, there is also evidence showing that diatoms can be utilized in improving SERS enhancement by optically coupling the GMRs of the diatom frustules with the LSPRs of the nanostructures. In this study, inexpensive, robust, and flexible diatom-based SERS platforms on box tapes are fabricated. For this purpose, diatom strips are fabricated using a template and assembled AgNPs using layer-by-layer method to obtain diatom/AgNP nanocomposite strips having six different layers. The fabricated SERS platforms are characterized using UV-Vis spectroscopy and scanning electron microscopy (SEM). The SERS performance of the platforms was evaluated using 4-aminothiophenol (4-ATP) and rhodamine-6G. The results demonstrate that SERS performance of the platforms are dependent on the number of layers of the structures. The SERS platform having highest SERS activity can be used for the characterization of any molecules of interest.

1.	Jeanmaire, D. L., and Van Duyne, R. P., Surface Raman Spectroelectrochemistry. 1. Heterocyclic, Aromatic, and Aliphatic- Amines Adsorbed on Anodized Silver Electrode // J. Electroanal. Chem.–1977–84.-P.1-20.
2.	Albrecht, M. G., and Creighton, J. A., Anomalously Intense Raman Spectra of Pyridine at a Silver Electrode // J. Am. Chem. Soc. - 1977-99.-P.5215-5217.
3.	Fanghui R., Jeremy C., Xiangyu W., Gregory L. R., and Alan X. W., Enhancing surface plasmon resonances of metallic nanoparticles by diatom biosilica // Optics Express-2013-21. N.13-P.15308-15313.
4.	Chen J., Qin G., Chen Q., Yu J., Cao F., Yang B., Ren Y., A synergistic combination of diatomaceous earth with Au nanoparticles as a periodically ordered, button-like substrate for SERS analysis of the chemical composition of eccrine sweat in latent fingerprints // Journal of Materials Chem.-2015-19.–P.1-38.
5.	De Tommasi E., De Luca A. C., Lavanga L., Dardano P.,  De Stefano M., De Stefano L., Langella C., Rendina I., Dholakia K. and Mazilu M., Biologically enabled sub-diffractive focusing // Optics Express–2014–22. N.22–P. 27214-27227