Journal article
A nanoscale optical biosensor: Real-time immunoassay in physiological buffer enabled by improved nanoparticle adhesion
Journal of Physical Chemistry B, Vol.107(8), pp.1772-1780
2003
DOI: 10.1021/jp022130v
Abstract
The shift in the extinction maximum, λmax, of the localized surface plasmon resonance (LSPR) spectrum of triangular Ag nanoparticles (∼90 nm wide and 50 nm high) is used to probe the interaction between a surface-confined antigen, biotin (B), and a solution-phase antibody, anti-biotin (AB). Exposure of biotin-functionalized Ag nanotriangles to 7 × 10-7 M < [AB] < 7 × 10-6 M caused a ∼38 nm red-shift in the LSPR λmax. The experimental normalized response of the LSPR λmax shift, (ΔR/ΔRmax), versus [AB] was measured over the concentration range 7 × 10-10 M < [AB] < 7 × 10-6 M. Comparison of the experimental data with the theoretical normalized response for a 1:1 binding model yielded values for the saturation response, ΔRmax = 38.0 nm, the surface-confined thermodynamic binding constant, Ka,surf = 4.5 × 107 M-1, and the limit of detection (LOD) < 7 × 10-10 M. The experimental saturation response was interpreted in terms of a closest-packed structural model for the surface B−AB complex in which the long axis ...
Details
- Title: Subtitle
- A nanoscale optical biosensor: Real-time immunoassay in physiological buffer enabled by improved nanoparticle adhesion
- Creators
- Jonathan C RibohAmanda J HaesAdam D McFarlandChanda Ranjit YonzonRichard P Van Duyne
- Resource Type
- Journal article
- Publication Details
- Journal of Physical Chemistry B, Vol.107(8), pp.1772-1780
- DOI
- 10.1021/jp022130v
- ISSN
- 1089-5647
- eISSN
- 1520-5207
- Language
- English
- Date published
- 2003
- Academic Unit
- Chemistry
- Record Identifier
- 9983985870402771
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