Polarization dependence technique of surface-enhanced infrared absorption with ATR configuration and its applications for solid-liquid interface measurements

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K14501
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Analytical chemistry
• Research Institution: Kyushu University of Health and Welfare (2019-2022); Shinshu University (2017-2018)
• Principal Investigator: Uchida Taro 九州保健福祉大学, 薬学部, 講師 (70581643)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 表面増強赤外 / 偏光 / 表面振動分光

Outline of Final Research Achievements

In this study, we investigated the polarization dependence of surface-enhanced infrared absorption spectroscopy coupled with ATR configuration (ATR-SEIRAS). ATR-SEIRAS measurements of metal surfaces with p-polarized light provided adsorbed molecular and bulk molecular information, whereas measuring with s-polarized light did not. We performed indication expansion of ATR-SEIRAS application by applying these findings to cases in which a clean surface cannot be used as a reference spectrum. Setting a spectrum measured with p-polarized light as a sample spectrum and a spectrum measured with s-polarized light as a reference spectrum, we were able to obtain an 'absolute spectrum' of molecules absorbed on the surface. This result allowed us to gain precise information about absorbed structure of the molecules on the surface. Furthermore, this measurement technique was able to perform the time-resolved measurement.

Free Research Field

分光分析化学

Academic Significance and Societal Importance of the Research Achievements

ATR-SEIRASでは、参照および試料スペクトルが必要となる。通常は試料の吸着のない表面をを測定し参照スペクトルとする。清浄表面を参照として測定できない場合、外部から摂動を与え、摂動の有無による差スペクトルを測定するが、さまざまな問題が起こり、スペクトルの解釈を間違えやすい。これらにより、これまで、ATR-SEIRASの使用範囲が限定さていた。しかし、本研究課題ではATR-SEIRASの偏光依存性を明らかにし、その性質を測定に応用し、簡便な測定系でこれまで測定が難しかった実験系が測定できることを示したことから有用な研究と考えられた。