| AVS 66th International Symposium & Exhibition | |
| Chemical Analysis and Imaging Interfaces Focus Topic | Thursday Sessions |
| Session CA+NS+SS+VT-ThA |
| Session: | Progress in Instrumentation and Methods for Spectro-microscopy of Interfaces |
| Presenter: | Scott Lea, Pacific Norththwest National Laboratory |
| Authors: | B.T. O'Callahan, Pacific Northwest National Laboratory M. Hentschel, University of Stuttgart, Germany M.B. Raschke, University of Colorado Boulder P.Z. El-Khoury, Pacific Northwest National Laboratory A.S. Lea, Pacific Norththwest National Laboratory |
| Correspondent: | Click to Email |
Surface enhanced infrared absorption (SEIRA) using resonant plasmonic nanoantennas enables zeptomolar detection sensitivity of (bio)analytes, although with diffraction limited spatial 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. In this presentation, we discuss our approach combining these two methods to image both continuous and sparse distributions of ferritin protein complexes 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. Through simulations of the recorded hyperspectral images, we extract the optical signatures of protein complex monolayers. This work paves the way for single protein identification and imaging through a combination of tip and antenna-enhanced IR nanoscopy.