Sonay, A.Y. | Çağlayan, A.B. | Çulha, Mustafa

Article | 2012 | Plasmonics7 ( 1 ) , pp.77 - 86

As the fundamental understanding of metal-light interactions gains solid grounds, further research has been devoted to construct novel structures that take full advantage of such unique interactions, which is called plasmonics. In this report, the preparation of Au-Ag core-shell structures obtained by coating the Au surface with peptide and Raman reporter molecule and depositing an Ag layer on it is reported. The prepared Au-Ag NPs are tested for their surface-enhanced Raman scattering (SERS) performance. The negatively charged peptides with three different lengths, which are 3 (P1), 15 (P2), and 21 (P3) amino acid long, were chemic . . .ally attached to 13 nm AuNPs along with Raman reporter molecule, carboxytetramethylrhodamine, and these modified AuNPs were coated with three different shell thickness of Ag metal. The prepared Au-Ag NPs were tested for their SERS performance and found that the Au-Ag NPs prepared with P2 and thickest shell performs best as SERS label. © 2011 Springer Science+Business Media, LLC Daha fazlası Daha az

Altunbek, M. | Çulha, Mustafa

Article | 2017 | Plasmonics12 ( 6 ) , pp.1749 - 1760

The conventional colorimetric assays based on measurement of the metabolic activity are routinely used to evaluate the cytotoxicity of nanomaterials (NMs). However, due to the varying absorbance properties of plasmonic NMs in the visible region of the spectrum, obtained results can be misleading. In this study, MTT, MTS, and WST-1 colorimetric cell viability assays were evaluated in the presence of gold (AuNPs) or silver nanoparticles (AgNPs). Since a living cell a complex system containing many molecular and ionic species, the plasmonic AuNP and AgNPs may selectively interact with intracellular components possessing thiol, amino, a . . .nd carboxyl group moieties change the aggregation behavior of the NMs and thus their absorbance. A series of UV/Vis and DLS experiments were conducted to understand the interference possibility of the tested plasmonic NMs. The results show that the AuNPs and AgNPs do not have absorption at the wavelength where MTT formazan is measured while the both NPs may interfere with absorbance of MTS and WST-1 formazan.The overall assessments show that MTT assay is more suitable for the cell viability evaluation of spherical AuNPs and AgNPs with an average diameter of 50 nm. This study also suggests that a preliminary ex situ evaluation of plasmonic nanoparticles can provide valuable information for the suitability of the assay. © 2016, Springer Science+Business Media New York Daha fazlası Daha az