Biointerphases

Journal for Biophysical Chemistry

Biointerphases Cover Image
Open Access

Benchtop chemistry for the rapid prototyping of label-free biosensors: Transmission localized surface plasmon resonance platforms

  • Wei-Ssu Liao1,
  • Xin Chen1,
  • Tinglu Yang1,
  • Edward T. Castellana1,
  • Jixin Chen1 and
  • Paul S. Cremer1Email author
Biointerphases4:40400080

https://doi.org/10.1116/1.3284738

Received: 8 December 2009

Accepted: 8 December 2009

Abstract

Herein, a simple label-free biosensor fabrication method is demonstrated based on transmission localized surface plasmon resonance (T-LSPR). The platform, which consists of a silver nanoparticle array, can be prepared in just a few minutes using benchtop chemistry. The array was made by a templating technique in conjunction with the photoreduction of Ag ions from solution. This metal surface was functionalized with biotin-linked thiol ligands for binding streptavidin molecules from solution. For an array of 19 nm diameter silver nanoparticles, a redshift in the T-LSPR spectrum of 24 nm was observed upon protein-ligand binding at saturation. The binding constant was found to be 2 × 1012 M−1. Platforms were also fabricated with silver nanoparticles of 34, 55, and 72 nm diameters. The maximum LSPR wavelength shift was nanoparticle size dependent and the maximum sensitivity was obtained with the smaller nanoparticles.