An Infrared Nanospectroscopy Technique for the Study of Electric-Field-Induced Molecular Dynamics.

Autor: Temperini ME; Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy.; Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, I-00161 Roma, Italy., Polito R; Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy., Venanzi T; Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, I-00161 Roma, Italy., Baldassarre L; Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy., Hu H; Center for Biomolecular Nanotechnologies, Istituto Italiano di Tecnologia, Via Barsanti 14, I-73010 Arnesano, Italy., Ciracì C; Center for Biomolecular Nanotechnologies, Istituto Italiano di Tecnologia, Via Barsanti 14, I-73010 Arnesano, Italy., Pea M; Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere 100, I-00133 Roma, Italy., Notargiacomo A; Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere 100, I-00133 Roma, Italy., Mattioli F; Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere 100, I-00133 Roma, Italy., Ortolani M; Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy.; Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, I-00161 Roma, Italy., Giliberti V; Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, I-00161 Roma, Italy.
Jazyk: angličtina
Zdroj: Nano letters [Nano Lett] 2024 Aug 14; Vol. 24 (32), pp. 9808-9815. Date of Electronic Publication: 2024 Aug 01.
DOI: 10.1021/acs.nanolett.4c01387
Abstrakt: Static electric fields play a considerable role in a variety of molecular nanosystems as diverse as single-molecule junctions, molecules supporting electrostatic catalysis, and biological cell membranes incorporating proteins. External electric fields can be applied to nanoscale samples with a conductive atomic force microscopy (AFM) probe in contact mode, but typically, no structural information is retrieved. Here we combine photothermal expansion infrared (IR) nanospectroscopy with electrostatic AFM probes to measure nanometric volumes where the IR field enhancement and the static electric field overlap spatially. We leverage the vibrational Stark effect in the polymer poly(methyl methacrylate) for calibrating the local electric field strength. In the relevant case of membrane protein bacteriorhodopsin, we observe electric-field-induced changes of the protein backbone conformation and residue protonation state. The proposed technique also has the potential to measure DC currents and IR spectra simultaneously, insofar enabling the monitoring of the possible interplay between charge transport and other effects.
Databáze: MEDLINE
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