Solution processed polydimethylsiloxane/gold nanostar flexible substrates for plasmonic sensing

Amane Shiohara, Judith Langer, Lakshminarayana Polavarapu, Luis M. Liz-Marzán

Research output: Contribution to journalArticleResearchpeer-review

97 Citations (Scopus)

Abstract

Gold nanostars can display tunable optical properties in the visible and near IR, which lead to strong electromagnetic field enhancement at their tips. We report generalized application of gold nanostars for ultrasensitive identification of molecules, based on both localized surface plasmon resonance (LSPR) and surface enhanced Raman scattering (SERS). We address the requirements of plasmonic sensors, related to sufficiently large areas where nanoparticles are uniformly immobilized with high density, as well as mechanical flexibility, which offers additional advantages for real-world applications. Gold nanostar monolayers were thus immobilized on transparent, flexible polydimethylsiloxane substrates, and their refractive index sensitivity and SERS performance were studied. The application of such substrates for LSPR based molecular sensing is demonstrated via detection of a model analyte, mercaptoundecanoic acid. We further demonstrate SERS-based pesticide detection on fruit skin, by simply covering the fruit surface with the flexible plasmonic substrate, at the area where the target molecule is to be detected. The transparency of the substrate allows SERS detection through backside excitation, thereby facilitating practical implementation.

Original languageEnglish
Pages (from-to)9817-9823
Number of pages7
JournalNanoscale
Volume6
Issue number16
DOIs
Publication statusPublished - 21 Aug 2014
Externally publishedYes

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