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Author Spaeth, P.; Adhikari, S.; Heyvaert, W.; Zhuo, X.; Garcia, I.; Liz-Marzan, L.M.; Bals, S.; Orrit, M.; Albrecht, W.
Title Photothermal circular dichroism measurements of single chiral gold nanoparticles correlated with electron tomography Type A1 Journal article
Year (down) 2022 Publication ACS Photonics Abbreviated Journal Acs Photonics
Volume 9 Issue 12 Pages 3995-4004
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Chemically synthesized metal nanoparticles with morphological chiral features are known to exhibit strong circular dichroism. However, we still lack understanding of the correlation between morphological and chiroptical features of plasmonic nanoparticles. To shed light on that question, single nanoparticle experiments are required. We performed photothermal circular dichroism measurements of single chiral and achiral gold nanoparticles and correlated the chiroptical response to the 3D morphology of the same nanoparticles retrieved by electron tomography. In contrast to an ensemble measurement, we show that individual particles within the ensemble display a broad distribution of strength and handedness of circular dichroism signals. Whereas obvious structural chiral features, such as helical wrinkles, translate into chiroptical ones, nanoparticles with less obvious chiral morphological features can also display strong circular dichroism signals. Interestingly, we find that even seemingly achiral nanoparticles can display large g-factors. The origin of this circular dichroism signal is discussed in terms of plasmonics and other potentially relevant factors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000884432100001 Publication Date 2022-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2330-4022 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7 Times cited 5 Open Access OpenAccess
Notes This work was supported by The Netherlands Organisation for Scientific Research (NWO) as part of the Open Technology Program (OTP, Project No. 16008) and by a Spinoza prize (M.O.) . W.A. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020 Program (Grant No. 797153, SOPMEN) . L.M.L.M. acknowledges funding from MCIN/AEI/10.13039/501100011033 (Grants PID2020-117779RB-I00 and MDM-2017-0720) . We thank Dr. Wolfgang L?fer for providing optical equipment. We also acknowledge the European Soft Matter Infrastructure (EUSMI: E201200468) . Approved Most recent IF: 7
Call Number UA @ admin @ c:irua:192098 Serial 7331
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Author Spaeth, P.; Adhikari, S.; Le, L.; Jollans, T.; Pud, S.; Albrecht, W.; Bauer, T.; Caldarola, M.; Kuipers, L.; Orrit, M.
Title Circular Dichroism Measurement of Single Metal Nanoparticles Using Photothermal Imaging Type A1 Journal article
Year (down) 2019 Publication Nano Letters Abbreviated Journal Nano Lett
Volume 19 Issue 12 Pages 8934-8940
Keywords A1 Journal article; Photothermal microscopy, chirality, circular dichroism, dissymmetry factor, linear dichroism, gold nanostructures; Electron Microscopy for Materials Science (EMAT) ;
Abstract Circular dichroism (CD) spectroscopy is a powerful optical technique for the study of chiral materials and molecules. It gives access to an enantioselective signal based on the differential absorption of right and left circularly polarized light, usually obtained through polarization analysis of the light transmitted through a sample of interest. CD is routinely used to determine the secondary structure of proteins and their conformational state. However, CD signals are weak, limiting the use of this powerful technique to ensembles of many molecules. Here, we experimentally realize the concept of photothermal circular dichroism, a technique that combines the enantioselective signal from circular dichroism with the high sensitivity of photothermal microscopy, achieving a superior signal-to-noise ratio to detect chiral nano-objects. As a proof of principle, we studied the chiral response of single plasmonic nanostructures with CD in the visible range, demonstrating a signal-to-noise ratio better than 40 with only 30 ms integration time for these nanostructures. The high signal-to-noise ratio allows us to quantify the CD signal for individual nanoparticles. We show that we can distinguish relative absorption differences for right circularly and left circularly polarized light as small as gmin = 4 × 10–3 for a 30 ms integration time with our current experimental settings. The enhanced sensitivity of our technique extends CD studies to individual nano-objects and opens CD spectroscopy to numbers of molecules much lower than those in conventional experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000502687500074 Publication Date 2019-12-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited Open Access
Notes This work was supported by The Netherlands Organisation for Scientific Research (NWO/OCW), as part of the Frontiers of Nanoscience (NanoFront) program, and Open Technology Program (OTP, Project No. 16008). M.C. acknowledges the financial support of the Kavli Institute of Nanoscience Delft through the KIND fellowships program. T.B. and L.K. acknowledge the financial support of the European Research Council (ERC) through Project 340438-CONSTANS. W.A. acknowledges an Individual Fellowship from the Marie Sklodowska-Curie actions (MSCA) under the EU’s Horizon 2020 program (Grant 797153, SOPMEN). The authors acknowledge Dr. Benjamin P. Isaacoff for his help in the initial steps of this project. P.S. thanks Martin Baaske for helpful discussions. M.C. thanks Dr. Felipe Bernal Arango for help with the 3D image rendering. Approved Most recent IF: 12.712
Call Number EMAT @ emat @c:irua:165087c:irua:165233 Serial 5439
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