Lock-in amplifier based peak force infrared microscopy
Lock-in amplifier based peak force infrared microscopy
复制标题
基于锁定放大器的峰值力红外显微镜
DOI：
10.1039/d2an01103d
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Xu, Xiaoji G.
中科院分区：
文献类型：
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作者：
Dorsa, Andrea;Xie, Qing;Wagner, Martin;Xu, Xiaoji G.
纳米级红外（nano-IR）显微镜通过原子力显微镜和红外辐射的集成，使空间分辨率低于阿贝衍射极限的无标签化学成像成为可能。峰力红外（PFIR）显微镜是一种新兴的纳米红外方法，它提供了非破坏性的多模态化学和机械表征能力，使用直接的光热信号产生机制。PFIR显微镜已被证明适用于广泛的异质样品，它甚至允许在流体相中操作。然而，目前的PFIR显微镜需要定制硬件配置和软件编程来进行实时信号采集和处理，这对PFIR的实现造成了很高的障碍。在这篇文章中，我们描述了一种基于锁定放大器的PFIR显微镜，它可以用通用的、市售的设备组装，而不需要特殊的硬件或软件编程。我们在结构聚合物混合物和块体的软物质以及大肠杆菌的生物细胞上证明了这种方法。基于锁定放大器的PFIR降低了PFIR显微镜的进入门槛，使其成为新用户具有竞争力的纳米红外方法。
Nanoscale infrared (nano-IR) microscopy enables label-free chemical imaging with a spatial resolution below Abbe's diffraction limit through the integration of atomic force microscopy and infrared radiation. Peak force infrared (PFIR) microscopy is one of the emerging nano-IR methods that provides non-destructive multimodal chemical and mechanical characterization capabilities using a straightforward photothermal signal generation mechanism. PFIR microscopy has been demonstrated to work for a wide range of heterogeneous samples, and it even allows operation in the fluid phase. However, the current PFIR microscope requires customized hardware configuration and software programming for real-time signal acquisition and processing, which creates a high barrier to PFIR implementation. In this communication, we describe a type of lock-in amplifier-based PFIR microscopy that can be assembled with generic, commercially available equipment without special hardware or software programming. We demonstrate this method on soft matters of structured polymer blends and blocks, as well as biological cells of E. coli. The lock-in amplifier-based PFIR reduces the entry barrier for PFIR microscopy and makes it a competitive nano-IR method for new users.