Dual-Color Peak Force Infrared Microscopy
Dual-Color Peak Force Infrared Microscopy
复制标题
双色峰值力红外显微镜
DOI：
10.1021/acs.analchem.1c04756
复制
发表时间：
2022
影响因子：
7.4
通讯作者：
Xu, Xiaoji G.
中科院分区：
文献类型：
--
作者：
Xie, Qing;Wiemann, Jared;Yu, Yan;Xu, Xiaoji G.
峰力红外(PFIR)显微镜通过对原子力显微镜(AFM)的光热机械检测，实现了空间分辨率在10 nm以下的纳米级红外成像。然而，它受到一个主要限制，即一次只能扫描一个红外频率来扫描AFM帧。为了克服这一限制，我们报告了一种双色PFIR显微镜，它可以在两个红外频率下同时成像。这种双色PFIR显微镜在比较不同红外频率的两幅图像时，绕过了AFM的帧漂移和失真的限制。我们使用表现出相分离的结构聚合物对该方法的性能和空间分辨率进行了基准测试。我们进一步展示了这项技术在生物样品成像中的应用，通过绘制大肠杆菌(E.Coli)细菌的细胞壁。在没有外在标记的情况下检测到细菌外膜的存在。这种双色PFIR显微镜可以同时对多个化学成分进行无损化学纳米成像，并将在化学反应的现场通道监测等潜在应用中发挥作用。
Peak force infrared (PFIR) microscopy achieves nanoscale infrared imaging at sub-10 nm spatial resolution through photothermal mechanical detection of atomic force microscopy (AFM). However, it suffers from a major limitation that only one infrared frequency can be scanned for an AFM frame at a time. To overcome this limitation, we report here dual-color PFIR microscopy that enables simultaneous imaging at two infrared frequencies. This dual-color PFIR microscopy bypasses the limitations of frame drift and distortion of AFM when comparing two images of different infrared frequencies. We benchmark the performance and spatial resolution of this method using structured polymers exhibiting phase separation. We further demonstrate the application of this technique in imaging biological samples by mapping the cell wall ofEscherichia coli(E. coli) bacteria. The presence of a bacterial outer membrane was detected without extrinsic labels. This dual-color PFIR microscopy enables simultaneous nondestructive chemical nanoimaging of multiple chemical components and will be useful for potential applications such asin situdual-channel monitoring of chemical reactions.