CIC nanoGUNE Consolider, 20018 Donostia - San Sebastián, Spain.
Nano Lett. 2012 Aug 8;12(8):3973-8. doi: 10.1021/nl301159v. Epub 2012 Jul 16.
We demonstrate Fourier transform infrared nanospectroscopy (nano-FTIR) based on a scattering-type scanning near-field optical microscope (s-SNOM) equipped with a coherent-continuum infrared light source. We show that the method can straightforwardly determine the infrared absorption spectrum of organic samples with a spatial resolution of 20 nm, corresponding to a probed volume as small as 10 zeptoliter (10(-20) L). Corroborated by theory, the nano-FTIR absorption spectra correlate well with conventional FTIR absorption spectra, as experimentally demonstrated with poly(methyl methacrylate) (PMMA) samples. Nano-FTIR can thus make use of standard infrared databases of molecular vibrations to identify organic materials in ultrasmall quantities and at ultrahigh spatial resolution. As an application example we demonstrate the identification of a nanoscale PDMS contamination on a PMMA sample.
我们展示了基于配备相干连续红外光源的散射型扫描近场光学显微镜（s-SNOM）的傅里叶变换红外纳米光谱学（nano-FTIR）。我们表明，该方法可以直接确定具有 20nm 空间分辨率的有机样品的红外吸收光谱，对应的探测体积小至 10 飞升（10(-20)L）。通过理论验证，nano-FTIR 吸收光谱与传统 FTIR 吸收光谱很好地相关，这在聚甲基丙烯酸甲酯（PMMA）样品的实验中得到了证明。因此，nano-FTIR 可以利用分子振动的标准红外数据库来识别超少量和超高空间分辨率的有机材料。作为一个应用实例，我们证明了在 PMMA 样品上纳米级 PDMS 污染的识别。
