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Precise control of distance between plasmonic surface‐enhanced Raman scattering substrate and analyte molecules with polyelectrolyte layers
Author(s) -
Prikhozhdenko Ekaterina S.,
Bratashov Daniil N.,
Atkin Vsevolod S.,
Kamyshinsky Roman A.,
Vasiliev Alexander L.,
Khlebtsov Boris N.,
Gorin Dmitry A.,
Möhwald Helmuth,
Yashchenok Alexey M.
Publication year - 2018
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5424
Subject(s) - polyelectrolyte , raman scattering , materials science , raman spectroscopy , molecule , coating , nanoparticle , layer by layer , nanotechnology , chemical engineering , layer (electronics) , chemistry , polymer , optics , composite material , physics , organic chemistry , engineering
The dependence of the surface‐enhanced Raman scattering (SERS) activity of small and large molecules on the number of polyelectrolyte monolayers covering the surface of gold nanocages (AuNCs) is investigated. The linkage of AuNCs to silica microparticles and the covering of its surface with additional polyelectrolyte layers are performed via layer‐by‐layer self‐assembly. Either three‐dimensional core–shell composite structures or hollow polyelectrolyte microspheres, obtained after the decomposition of solid templates, can be fabricated with coating thickness controlled with nanometer precision. Besides an obvious decrease of the signal intensity with increasing distance between plasmonic nanoparticle surface and Raman active molecules, there is a different signal dependence on the last layer charge for samples in water and air. The dependence of SERS signals on the number of layers also shows the difference for layers with and without thermal annealing, thus providing insight into changes in the structure of polyelectrolyte matrix. The obtained signal dependence is used to investigate the transport of low molecular weight analytes through polyelectrolyte layers and molecule interactions with polyelectrolyte chains, thus providing information about the internal layer structure that can not be obtained by direct measurements.