Imaging biological systems with simultaneous intrinsic chemical specificity and nanometer spatial resolution in their typical native liquid environment has remained a long-standing challenge. In this paper we demonstrate a general approach of chemical nanoimaging in liquid based on infrared scattering scanning near-field optical microscopy (IR $$s$$-SNOM). It is enabled by combining AFM operation in a fluid cell with evanescent IR illumination via total internal reflection, which provides spatially confined excitation for minimized IR water absorption, reduced far-field background, and enhanced directional signal emission and sensitivity. We demonstrate in-liquid IR $$s$$-SNOM vibrational nanoimaging and conformational identification of catalase nano-crystals and spatio-spectral analysis of biomimetic peptoid sheets with monolayer sensitivity and chemical specificity at the few zeptomole level. This work establishes the principles of in-liquid and in-situ IR $$s$$-SNOM spectroscopic chemical nano-imaging and its general applicability to biomolecular, cellular, catalytic, electrochemical, or other interfaces and nano-systems in liquids or solutions.
O’Callahan, Brian T., et al. "In Liquid Infrared Scattering Scanning Near-Field Optical Microscopy for Chemical and Biological Nanoimaging." Nano Letters, vol. 20, no. 6, May. 2020. https://doi.org/10.1021/acs.nanolett.0c01291
O’Callahan, Brian T., Park, Kyoung-Duck, Novikova, Irina V., Jian, Tengyue, Chen, Chun-Long, Muller, Eric A., El-Khoury, Patrick Z., Raschke, Markus B., & Lea, A. Scott (2020). In Liquid Infrared Scattering Scanning Near-Field Optical Microscopy for Chemical and Biological Nanoimaging. Nano Letters, 20(6). https://doi.org/10.1021/acs.nanolett.0c01291
O’Callahan, Brian T., Park, Kyoung-Duck, Novikova, Irina V., et al., "In Liquid Infrared Scattering Scanning Near-Field Optical Microscopy for Chemical and Biological Nanoimaging," Nano Letters 20, no. 6 (2020), https://doi.org/10.1021/acs.nanolett.0c01291
@article{osti_1631996,
author = {O’Callahan, Brian T. and Park, Kyoung-Duck and Novikova, Irina V. and Jian, Tengyue and Chen, Chun-Long and Muller, Eric A. and El-Khoury, Patrick Z. and Raschke, Markus B. and Lea, A. Scott},
title = {In Liquid Infrared Scattering Scanning Near-Field Optical Microscopy for Chemical and Biological Nanoimaging},
annote = {Imaging biological systems with simultaneous intrinsic chemical specificity and nanometer spatial resolution in their typical native liquid environment has remained a long-standing challenge. In this paper we demonstrate a general approach of chemical nanoimaging in liquid based on infrared scattering scanning near-field optical microscopy (IR $s$-SNOM). It is enabled by combining AFM operation in a fluid cell with evanescent IR illumination via total internal reflection, which provides spatially confined excitation for minimized IR water absorption, reduced far-field background, and enhanced directional signal emission and sensitivity. We demonstrate in-liquid IR $s$-SNOM vibrational nanoimaging and conformational identification of catalase nano-crystals and spatio-spectral analysis of biomimetic peptoid sheets with monolayer sensitivity and chemical specificity at the few zeptomole level. This work establishes the principles of in-liquid and in-situ IR $s$-SNOM spectroscopic chemical nano-imaging and its general applicability to biomolecular, cellular, catalytic, electrochemical, or other interfaces and nano-systems in liquids or solutions.},
doi = {10.1021/acs.nanolett.0c01291},
url = {https://www.osti.gov/biblio/1631996},
journal = {Nano Letters},
issn = {ISSN 1530-6984},
number = {6},
volume = {20},
place = {United States},
publisher = {American Chemical Society},
year = {2020},
month = {05}}
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER); National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES); National Research Foundation of Korea (NRF)
Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, Vol. 361, Issue 1813https://doi.org/10.1098/rsta.2003.1279