Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
Institute of Bioanalytics and Agro-Metabolomics, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenzstr. 20, 3430, Tulln, Austria.
Anal Bioanal Chem. 2020 May;412(14):3447-3456. doi: 10.1007/s00216-020-02546-3. Epub 2020 Mar 31.
During recent years, mid-infrared (MIR) spectroscopy has matured into a versatile and powerful sensing tool for a wide variety of analytical sensing tasks. Attenuated total reflection (ATR) techniques have gained increased interest due to their potential to perform non-destructive sensing tasks close to real time. In ATR, the essential component is the sampling interface, i.e., the ATR waveguide and its material properties interfacing the sample with the evanescent field ensuring efficient photon-molecule interaction. Gallium arsenide (GaAs) is a versatile alternative material vs. commonly used ATR waveguide materials including but not limited to silicon, zinc selenide, and diamond. GaAs-based internal reflection elements (IREs) are a new generation of semiconductor-based waveguides and are herein used for the first time in direct spectroscopic applications combined with conventional Fourier transform infrared (FT-IR) spectroscopy. Next to the characterization of the ATR waveguide, exemplary surface reactions were monitored, and trace-level analyte detection via signal amplification taking advantage of surface-enhanced infrared absorption (SEIRA) effects was demonstrated. As an example of real-world relevance, the mycotoxin aflatoxin B1 (AFB1) was used as a model analyte in food and feed safety analysis. Graphical abstract.
近年来，中红外（MIR）光谱技术已经发展成为一种多功能且强大的传感工具，适用于各种分析传感任务。由于其具有实时进行非破坏性传感任务的潜力，衰减全反射（ATR）技术引起了越来越多的关注。在 ATR 中，基本组件是采样接口，即 ATR 波导及其材料特性，将样品与倏逝场连接，以确保有效的光子-分子相互作用。砷化镓（GaAs）是一种通用的替代材料，可用于替代包括但不限于硅、硒化锌和金刚石等常用的 ATR 波导材料。基于 GaAs 的内反射元件（IRE）是新一代半导体基波导，目前首次在与传统傅里叶变换红外（FT-IR）光谱相结合的直接光谱应用中使用。除了对 ATR 波导进行表征外，还监测了示例表面反应，并利用表面增强红外吸收（SEIRA）效应进行了信号放大，从而实现痕量分析物的检测。作为实际相关性的一个例子，黄曲霉毒素 B1（AFB1）被用作食品和饲料安全分析中的模型分析物。示意图。
