Gkogkou Dimitra, Shaykhutdinov Timur, Kratz Christoph, Oates Thomas W H, Hildebrandt Peter, Weidinger Inez M, Ly Khoa Hoang, Esser Norbert, Hinrichs Karsten
Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., ISAS Berlin, Schwarzschildstr. 8, 12489 Berlin, Germany.
Technische Universität Berlin, Institut für Chemie, Sekr. PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany.
Analyst. 2019 Sep 7;144(17):5271-5276. doi: 10.1039/c9an00839j. Epub 2019 Jul 31.
In the last few decades, the use of plasmonics in vibrational spectroscopy has expanded the scope of (bio)analytical investigations. Nevertheless, there is a demand for a combined platform that can be simultaneously efficient for Surface Enhanced Raman Scattering (SERS) and Surface Enhanced Infrared Absorption (SEIRA). Here, we present a solution on the basis of a plasmonic Ag nanoparticle layer with a thickness gradient. The optical resonance along the layer varies from the visible to the infrared range offering optimal and intermediate sites for SERS and SEIRA of the analyte molecule (mercaptobenzonitrile). Enhancement factors for the same mode were determined to be ca. 10 and 170 for SERS and SEIRA, respectively. We present a full optical and vibrational characterization and demonstrate further tunability. The platform resolves reproducibility and comparability issues by a combination of the two methods. It also offers individualized solutions for different investigation conditions, i.e. a choice between excitation wavelengths and resonant Raman molecules. The multiple applicabilities of the presented unifying substrate can contribute to the expansion of the vibrational spectroscopic field and to analytics.
在过去几十年中，等离激元学在振动光谱学中的应用拓展了（生物）分析研究的范围。然而，人们需要一个能同时高效用于表面增强拉曼散射（SERS）和表面增强红外吸收（SEIRA）的组合平台。在此，我们基于具有厚度梯度的等离激元银纳米颗粒层提出了一种解决方案。沿该层的光学共振从可见光范围变化到红外范围，为分析物分子（巯基苯甲腈）的SERS和SEIRA提供了最佳和中间位点。对于同一模式，SERS和SEIRA的增强因子分别确定为约10和170。我们给出了完整的光学和振动表征，并展示了进一步的可调性。该平台通过两种方法的结合解决了重现性和可比性问题。它还为不同的研究条件提供了个性化解决方案，即在激发波长和共振拉曼分子之间进行选择。所提出的统一基底的多种适用性有助于拓展振动光谱学领域并推动分析学发展。
