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Title: Ultrasensitive Tip- and Antenna-Enhanced Infrared Nanoscopy of Protein Complexes

Abstract

Surface enhanced infrared absorption (SEIRA) us-ing resonant plasmonic nanoantennas enables zeptomolar detection sensitivity of (bio)analytes, although with diffraction limited spa-tial resolution. In contrast, infrared scattering-scanning near-field optical microscopy (IR s-SNOM) allows simultaneous imaging and spectroscopy with nanometer spatial resolution through vibrational coupling to the antenna mode of a probe tip. Herein, we combine these two approaches to image distributions of ferritin protein com-plexes adsorbed onto IR-resonant Au nanoantennas. The joint tip- and antenna-enhancement yields single protein complex sensitivity due to coupling with the vibrational modes of the bioanalytes. The coupling is revealed through IR s-SNOM spectra in the form of Fano lineshapes, which can be modelled using coupled harmonic oscillators. The role of the antenna resonance frequency on the cou-pling strength and the sensitivity is explored. Inhomogeneities in protein density within the film can be detected at single protein complex level. This work paves the way for single protein identi-fication and imaging through a combination of tip- and antenna-enhanced IR nanoscopy.

Authors:
 [1];  [2];  [3]; ORCiD logo [1]; ORCiD logo [1]
  1. BATTELLE (PACIFIC NW LAB)
  2. Universitat Stuttgart
  3. University of Colorado at Boulder
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1571484
Report Number(s):
PNNL-SA-144661
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry C
Additional Journal Information:
Journal Volume: 123; Journal Issue: 28
Country of Publication:
United States
Language:
English

Citation Formats

O'Callahan, Brian T., Hentschel, Mario, Raschke, Mark B., El-Khoury, Patrick Z., and Lea, A Scott. Ultrasensitive Tip- and Antenna-Enhanced Infrared Nanoscopy of Protein Complexes. United States: N. p., 2019. Web. doi:10.1021/acs.jpcc.9b05777.
O'Callahan, Brian T., Hentschel, Mario, Raschke, Mark B., El-Khoury, Patrick Z., & Lea, A Scott. Ultrasensitive Tip- and Antenna-Enhanced Infrared Nanoscopy of Protein Complexes. United States. doi:10.1021/acs.jpcc.9b05777.
O'Callahan, Brian T., Hentschel, Mario, Raschke, Mark B., El-Khoury, Patrick Z., and Lea, A Scott. Thu . "Ultrasensitive Tip- and Antenna-Enhanced Infrared Nanoscopy of Protein Complexes". United States. doi:10.1021/acs.jpcc.9b05777.
@article{osti_1571484,
title = {Ultrasensitive Tip- and Antenna-Enhanced Infrared Nanoscopy of Protein Complexes},
author = {O'Callahan, Brian T. and Hentschel, Mario and Raschke, Mark B. and El-Khoury, Patrick Z. and Lea, A Scott},
abstractNote = {Surface enhanced infrared absorption (SEIRA) us-ing resonant plasmonic nanoantennas enables zeptomolar detection sensitivity of (bio)analytes, although with diffraction limited spa-tial resolution. In contrast, infrared scattering-scanning near-field optical microscopy (IR s-SNOM) allows simultaneous imaging and spectroscopy with nanometer spatial resolution through vibrational coupling to the antenna mode of a probe tip. Herein, we combine these two approaches to image distributions of ferritin protein com-plexes adsorbed onto IR-resonant Au nanoantennas. The joint tip- and antenna-enhancement yields single protein complex sensitivity due to coupling with the vibrational modes of the bioanalytes. The coupling is revealed through IR s-SNOM spectra in the form of Fano lineshapes, which can be modelled using coupled harmonic oscillators. The role of the antenna resonance frequency on the cou-pling strength and the sensitivity is explored. Inhomogeneities in protein density within the film can be detected at single protein complex level. This work paves the way for single protein identi-fication and imaging through a combination of tip- and antenna-enhanced IR nanoscopy.},
doi = {10.1021/acs.jpcc.9b05777},
journal = {Journal of Physical Chemistry C},
number = 28,
volume = 123,
place = {United States},
year = {2019},
month = {7}
}