Original Article

Citation: Light: Science & Applications (2017) 6, e17042; doi:10.1038/lsa.2017.42
Published online 25 August 2017

Superior LSPR substrates based on electromagnetic decoupling for on-a-chip high-throughput label-free biosensing
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Srdjan S Aćimović1, Hana Šípová1, Gustav Emilsson2, Andreas B Dahlin2, Tomasz J Antosiewicz1,3 and Mikael Käll1

  1. 1Department of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
  2. 2Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
  3. 3Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland

Correspondence: SS Aćimović, E-mail: srdjan.acimovic@chalmers.se; M Käll, E-mail: mikael.kall@chalmers.se

Received 22 November 2016; Revised 2 March 2017; Accepted 8 March 2017
Accepted article preview online 10 March 2017

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Abstract

Localized surface plasmon resonance (LSPR) biosensing based on supported metal nanoparticles offers unparalleled possibilities for high-end miniaturization, multiplexing and high-throughput label-free molecular interaction analysis in real time when integrated within an opto-fluidic environment. However, such LSPR-sensing devices typically contain extremely large regions of dielectric materials that are open to molecular adsorption, which must be carefully blocked to avoid compromising the device readings. To address this issue, we made the support essentially invisible to the LSPR by carefully removing the dielectric material overlapping with the localized plasmonic fields through optimized wet-etching. The resulting LSPR substrate, which consists of gold nanodisks centered on narrow SiO2 pillars, exhibits markedly reduced vulnerability to nonspecific substrate adsorption, thus allowing, in an ideal case, the implementation of thicker and more efficient passivation layers. We demonstrate that this approach is effective and fully compatible with state-of-the-art multiplexed real-time biosensing technology and thus represents the ideal substrate design for high-throughput label-free biosensing systems with minimal sample consumption.

Keywords:

biosensing; hyperspectral; lab-on-a-chip; LSPR; nonspecific adsorption