Emergence of a Low-Energy Peak in the Smoothed Absolute Value Circular Dichroism Spectra of Small Helical Gold Nanorods.

Autor: Hodgins HP; Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada., Foley JJ 4th; Department of Chemistry, University of North Carolina Charlotte, 9201 University City Blvd, Charlotte, North Carolina 28223, United States., Govorov AO; Department of Physics and Astronomy, Clippinger Research Laboratories, Ohio University, Athens, Ohio 45701, United States., Gray SK; Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States., Hamilton IP; Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada.
Jazyk: angličtina
Zdroj: ACS omega [ACS Omega] 2024 Jan 25; Vol. 9 (5), pp. 5224-5229. Date of Electronic Publication: 2024 Jan 25 (Print Publication: 2024).
DOI: 10.1021/acsomega.3c04943
Abstrakt: We calculate, using time-dependent density functional theory, absorption and circular dichroism (CD) spectra for a series of small helical gold nanorod structures with a width of 0.6 nm and length increasing from 0.7 nm for Au 24 to 1.9 nm for Au 56 . For a low-energy window, ranging from 1.7 to 4.1 eV, broadening the lines in the absorption spectra results in a low energy peak which previous studies have identified as the (localized) plasmon resonance. As expected, the absorption peak position of the plasmon resonance systematically redshifts as the length of the nanorod increases. However, trends in the CD and straightforwardly broadened CD spectra are more difficult to discern. We introduce the idea of an absolute value CD spectrum and show that broadening the lines results in a low energy peak that has not previously been reported. The peak position systematically redshifts as the length of the nanorod increases but over a significantly smaller range than that for the absorption spectrum.
Competing Interests: The authors declare no competing financial interest.
(© 2024 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
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