Date

2020-01-01

Author

Demirtas, Özge
Akdemir, Ozan
Coşkun, Åžahin
Ünalan, Hüsnü Emrah
Bek, Alpan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

140
views

0
downloads

Cite This

© 2020 SPIE.In this work, we report the feasibility of the silver nanowire (AgNW) foils as highly-sensitive, reproducible and facile detection tools for surface-enhanced Raman spectroscopy (SERS) applications. These flexible and free-standing AgNW foils, fabricated by vacuum filtration method following a modified polyol synthesis of AgNWs, are adequately structured for both biological specimen filtering and trace amount of molecule detection simultaneously. The compatibility of AgNW foil in SERS is investigated by using a Raman active molecule of different steric volumes across the filter cross-section. We have shown that AgNW foils exhibit extremely strong SERS activity with detection limit up to 10-9 M of crystal violet (CV) molecule with 20% variation over ∼cm2 , revealing reliable homogeneity of the acquired signal. While naturally occurring polyvinylpyrrolidone (PVP) layer during polyol synthesis contribute to controlled aggregation, oxidation prevention, and size - shape control purposes, it also creates a major challenge for obtaining enormous enhancement factors. However, controlled thickness of aluminum oxide (Al2O3) coating on PVP@AgNW foils affords to achieve higher enhancement factors than the uncoated ones. What is interesting is that the maximum intensity is achieved from two cycles of Al2O3 deposited on AgNW foils. This is attributed to the two different origins: first, a higher adsorption affinity of CV molecules to Al2O3 layer than PVP layer; second, tunneling barrier formation against quantum tunneling effects.

URI

https://hdl.handle.net/11511/70241

Collections

Department of Metallurgical and Materials Engineering, Conference / Seminar