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Distance control in-between plasmonic nanoparticles via biological and polymeric spacers

In the present review article, the possibilities of generating such groupings by using biological and polymeric spacers in between the nanoparticles are described. In particular, streptavidin–biotin and DNA are discussed as biological spacers, and layer-by-layer (LbL) assembled films as polymeric spacers.

Xiang Yua; Dang Yuan Leib, Faheem Amina, Raimo Hartmanna, Guillermo P. Acunac, Andrés Guerrero-Martínezd, Stefan A. Maiere, Philip Tinnefeldc, Susana Carregal-Romeroa,f, Wolfgang J. Paraka,g, 

 

Fachbereich Physik, Philipps Universität Marburg, Marburg, Germany; b Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China; c NanoBioScience Group, Institute for Physical and Theoretical Chemistry, TU Braunschweig, Braunschweig, Germany; d Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain; e Department of Physics, Imperial College London, London, United Kingdom f BIONAND, Andalucian Center for Nanomedicine & Biotechnology, Málaga, Spain; g CIC Biomagune, San Sebastian, Spain 

 

  Nanotoday, 2013, 8 (5), pp 480–493 

Abstract

For detailed experimental studies about the electromagnetic coupling between plasmonic nanoparticles, precisely-controlled nanoparticle groupings with adjustable inter-particle distance would be required. In the present review article, the possibilities of generating such groupings by using biological and polymeric spacers in between the nanoparticles are described. In particular, streptavidin–biotin and DNA are discussed as biological spacers, and layer-by-layer (LbL) assembled films as polymeric spacers. The concepts are visualized by experimental data, which also point out the pitfalls and current limits of such approaches. Calculation results reveal that while small variations in the diameter of plasmonic cores lead to small changes, small variations in the inter-particle distance due to soft linkers result in significant changes in plasmonic coupling. In the case of protein-based spacers, nonspecific adsorption has to be considered as an obstacle for the formation of controlled groupings.