naa a22 4500 510815812 CHVBK 20180411083507.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s11468-012-9420-y doi (NATIONALLICENCE)springer-10.1007/s11468-012-9420-y Comparative Study of Plasmonic Properties of Cysteine-Functionalized Gold and Silver Nanoparticle Aggregates [Elektronische Daten] [Anikó Szalai, Áron Sipos, Edit Csapó, László Tóth, Mária Csete, Imre Dékány] The absorptance spectra of gold and silver nanoparticle (NP) aqueous dispersions were measured by UV-visible spectroscopy and computed numerically by finite element method. Both NPs were functionalized by l-cysteine amino acid (Cys) in order to develop aggregate-based localized surface plasmon resonance biosensors. Absorptance spectra measured at an analogous pH value of ∼4.9 were compared, where Au-Cys conjugates have moderately split spectra with two commensurate maxima, while Ag-Cys conjugates exhibit the most pronounced secondary peak according to the highest degree of aggregation. The purpose of our theoretical study was to determine the simplest linear chain-like and wavy aggregate geometries, which result in maxima matching the measured peaks. The aggregates were characterized by N number and d diameter of NPs, g gap between the NPs, and t thickness of the l-cysteine covering. By tuning the angle of incidence and E -field oscillation direction in p-polarized light with respect to the aggregates, the contribution of longitudinal and transversal modes was varied. The comparison of measurements and computations revealed that spectra measured on bioconjugate dispersions include effects of numerous aggregates with various geometries, illuminated from different directions and are influenced by inter-aggregate coupling. Inspecting the normalized E -field distribution surrounding the aggregates, it was shown that fundamentally different multipolar modes can be identified at primary and secondary absorptance maxima, due to coupled plasmonic resonances on NPs. Springer Science+Business Media, LLC, 2012 Nanoparticle aggregates nationallicence LSPR spectra nationallicence Coupled plasmonic resonances nationallicence Array effect nationallicence Szalai Anikó Department of Optics and Quantum Electronics, University of Szeged, Dóm tér. 9., 6720, Szeged, Hungary aut Sipos Áron Department of Optics and Quantum Electronics, University of Szeged, Dóm tér. 9., 6720, Szeged, Hungary aut Csapó Edit Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged, Aradi vértanuk tere 1., 6720, Szeged, Hungary aut Tóth László Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Aradi vértanuk tere 1., 6720, Szeged, Hungary aut Csete Mária Department of Optics and Quantum Electronics, University of Szeged, Dóm tér. 9., 6720, Szeged, Hungary aut Dékány Imre Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged, Aradi vértanuk tere 1., 6720, Szeged, Hungary aut Plasmonics Springer US; http://www.springer-ny.com 8/1(2013-03-01), 53-62 1557-1955 8:1<53 2013 8 11468 https://doi.org/10.1007/s11468-012-9420-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11468-012-9420-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Szalai Anikó Department of Optics and Quantum Electronics, University of Szeged, Dóm tér. 9., 6720, Szeged, Hungary aut NATIONALLICENCE 700 1- Sipos Áron Department of Optics and Quantum Electronics, University of Szeged, Dóm tér. 9., 6720, Szeged, Hungary aut NATIONALLICENCE 700 1- Csapó Edit Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged, Aradi vértanuk tere 1., 6720, Szeged, Hungary aut NATIONALLICENCE 700 1- Tóth László Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Aradi vértanuk tere 1., 6720, Szeged, Hungary aut NATIONALLICENCE 700 1- Csete Mária Department of Optics and Quantum Electronics, University of Szeged, Dóm tér. 9., 6720, Szeged, Hungary aut NATIONALLICENCE 700 1- Dékány Imre Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged, Aradi vértanuk tere 1., 6720, Szeged, Hungary aut NATIONALLICENCE 773 0- Plasmonics Springer US; http://www.springer-ny.com 8/1(2013-03-01), 53-62 1557-1955 8:1<53 2013 8 11468 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer