Tip-enhanced infrared nanospectroscopy via molecular expansion force detection
Tip-enhanced infrared nanospectroscopy via molecular expansion force detection
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DOI：
10.1038/nphoton.2013.373
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发表时间：
2014-04-01
期刊：
影响因子：
35
通讯作者：
Belkin, Mikhail A.
中科院分区：
文献类型：
--
作者：
Lu, Feng;Jin, Mingzhou;Belkin, Mikhail A.
分子指纹区的中红外吸收光谱广泛用于化学鉴定和使用红外吸收光谱数据库的定量分析。具有纳米空间分辨率的中红外光谱技术在材料和生命科学中的应用是非常理想的。目前，散射近场扫描光学显微镜（1-6）被认为是环境条件下纳米级中红外光谱最灵敏的技术。在这里，我们表明，纳米级的中红外光谱可以通过检测原子力显微镜尖端上的分子施加的机械力，光激发，具有可比或更高的灵敏度。中红外纳米光谱的机械方法导致一个简单的光学设置，不像散射近场扫描光学显微镜，不需要低温冷却的中红外探测器，易于对齐，并且不受样品散射的影响。
Mid-infrared absorption spectroscopy in the molecular fingerprint region is widely used for chemical identification and quantitative analysis employing infrared absorption spectra databases. The ability to perform mid-infrared spectroscopy with nanometre spatial resolution is highly desirable for applications in materials and life sciences. At present, scattering near-field scanning optical microscopy(1-6) is considered to be the most sensitive technique for nanoscale mid-infrared spectroscopy under ambient conditions. Here, we demonstrate that nanoscale mid-infrared spectra can be obtained with comparable or higher sensitivity by detecting mechanical forces exerted by molecules on the atomic force microscope tip on light excitation. The mechanical approach to mid-infrared nanospectroscopy results in a simple optical set-up that, unlike scattering near-field scanning optical microscopy, requires no cryogenically cooled mid-infrared detectors, is easy to align, and is not affected by sample scattering.