Nanofluidic devices have offered us fascinating analytical platforms for chemical and bioanalysis by exploiting unique properties of liquids and molecules confined in nanospaces. The increasing interests in nanofluidic analytical devices have triggered the development of new robust and sensitive detection techniques, especially label-free ones. IR absorption spectroscopy is one of the most powerful biochemical analysis methods for identification and quantitative measurement of chemical species in the label-free and non-invasive fashion. However, the low sensitivity and the difficulties in fabrication of IR-compatible nanofluidic devices are major obstacles that restrict the applications of IR spectroscopy in nanofluidics. Here, we realized the bonding of CaF₂ and SiO₂ at room temperature and demonstrated an IR-compatible nanofluidic device that allowed the IR spectroscopy in a wide range of mid-IR regime. We also performed the integration of metal-insulator-metal perfect absorber metamaterials into nanofluidic devices for plasmon-enhanced infrared absorption spectroscopy with ultrahigh sensitivity. This study also shows a proof-of-concept of the multi-band absorber by combining different types of nanostructures. The results indicate the potential of implementing metamaterials in tracking several characteristic molecular vibrational modes simultaneously, making it possible to identify molecular species in mixture or complex biological entities.

中文翻译：

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等离子增强红外吸收光谱的红外兼容纳米流体器件的制备

纳米流体设备通过利用限制在纳米空间中的液体和分子的独特特性，为我们提供了用于化学和生物分析的引人入胜的分析平台。人们对纳米流体分析设备的兴趣日益增长，引发了新的鲁棒性和灵敏性检测技术的发展，尤其是无标签技术。红外吸收光谱法是最强大的生化分析方法之一，以无标记和无创的方式鉴定和定量测量化学物质。然而，低灵敏度和制造红外兼容纳米流体装置的困难是限制红外光谱在纳米流体中的应用的主要障碍。在这里，我们实现了CaF ₂和SiO ₂的键合并在室温下显示了红外兼容的纳米流体装置，该装置可以在广泛的中红外范围内进行红外光谱分析。我们还进行了将金属-绝缘体-金属完美吸收体超材料集成到纳米流体装置中的超高灵敏度等离激元增强红外吸收光谱的研究。这项研究还通过组合不同类型的纳米结构显示了多频带吸收器的概念验证。结果表明，利用超材料同时跟踪几种特征分子振动模式的潜力，使鉴定混合物或复杂生物实体中的分子种类成为可能。