Park Keunhan, Lee Jungchul, Bhargava Rohit, King William P
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Illinois 61801, USA.
Anal Chem. 2008 May 1;80(9):3221-8. doi: 10.1021/ac702423c. Epub 2008 Mar 27.
Simultaneous structural and chemical characterization of materials at the nanoscale is both an immediate need and an ongoing challenge. This article reports a route to address this need, which can be rapidly adopted by practitioners, by combining the benefits of widely available scanning probe microscopy and vibrational microspectrometry. In an atomic force microscope (AFM), the probe tip can provide a nanoscale topographic image. Here, we use a temperature-controlled probe tip to selectively acquire an analyte from a specified location and determine its mass in a thermogravimetric manner. The tip is then analyzed via complementary Raman and Fourier transform infrared microspectrometers, providing a molecular characterization of samples down to the femtogram level in minutes. The probe can be self-cleaned and employed for repeated use by rapidly heating it to vaporize the analyte. By combining the established analytical modalities of AFM and vibrational spectrometry, a complete physical and molecular characterization of nanoscale domains is possible: mass determination is facile, thermal analyses can be integrated on the probe, and the obtained spectral data can be related to existing knowledge bases.
在纳米尺度上对材料进行结构和化学的同步表征既是当下的需求，也是一项持续面临的挑战。本文报道了一种满足这一需求的方法，通过结合广泛使用的扫描探针显微镜和振动光谱仪的优势，从业者可以迅速采用该方法。在原子力显微镜（AFM）中，探针尖端可以提供纳米级的形貌图像。在这里，我们使用一个温度可控的探针尖端从指定位置选择性地获取分析物，并以热重法确定其质量。然后通过互补的拉曼光谱仪和傅里叶变换红外光谱仪对尖端进行分析，在几分钟内就能对低至飞克级的样品进行分子表征。通过快速加热探针使分析物汽化，探针可以自我清洁并重复使用。通过结合AFM已有的分析方式和振动光谱法，可以对纳米级区域进行完整的物理和分子表征：质量测定简便易行，热分析可以集成到探针上，并且所获得的光谱数据可以与现有的知识库相关联。
