Near-Field Vibrational Spectroscopy: Infrared and Raman Studies at High Spatial Resolution

Published

January 1, 2002

Author(s)

Stephan J. Stranick, D B. Chase, Chris A. Michaels

Abstract

The ability to measure chemical bond changes on the nanometer scale is of critical importance for the characterization of catalytic materials, engineered materials and surfaces relevant to biological problems. In this paper, we will outline the development of a technique for in-situ, non-destructive measurements of site-specific chemistry on the nanometer scale. The technique involves coupling the high spatial resolution of near-field scanning optical microscopy (NSOM) with the chemical specificity of vibrational spectroscopy. The combination of the sub-diffraction spatial resolution attainable in the near-field with the high chemical specificity of vibrational spectroscopy promised a powerful new analytical instrument that would overcome critical measurement limitations of both far-field vibrational microscopes (low spatial resolution) and scanned probe microscopes (lack of chemical specificity). Our efforts have been driven by the potential widespread utility of such an instrument. Significant technical challenges involve answering fundamental NSOM metrological questions about the physical basis of image contrast and surmounting the daunting technical barriers to the realization of Raman scattering and infrared absorption as near-field contrast mechanisms. Extension of these capabilities to longer wavelengths (microwaves) will providing scientists and engineers with tools for both compositional (chemical identification) and performance (dielectric response) mapping of material at finer and finer length scales. The ability to elucidate site-specific chemistry on the nanometer scale will continue to grow in importance and impact key applications in the fields of biotechnology, materials science, nanotechnology, and high throughput experimentation.

Citation

American Pharmaceutical Review

Volume

5

Pub Type

Journals

Keywords

chemical imaging, infrared, nanoscale, near-field, NSOM, Raman

Citation

Stranick, S. , Chase, D. and Michaels, C. (2002), Near-Field Vibrational Spectroscopy: Infrared and Raman Studies at High Spatial Resolution, American Pharmaceutical Review (Accessed March 10, 2025)