Plasmon-Enhanced Colorimetric ELISA with Single Molecule Sensitivity
Artikel i vetenskaplig tidskrift, 2011

Robust but ultrasensitive biosensors with a capability of detecting low abundance biomarkers could revolutionize clinical diagnostics and enable early detection of cancer, neurological diseases, and infections. We utilized a combination of localized surface plasmon resonance (LSPR) refractive index sensing and the well-known enzyme-linked immunosorbent assay to develop a simple colorimetric biosensing methodology with single molecule sensitivity. The technique is based on spectral imaging of a large number of isolated gold nanoparticles. Each particle binds a variable number of horseradish peroxidase (HRP) enzyme molecules that catalyze a localized precipitation reaction at the particle surface. The enzymatic reaction dramatically amplifies the shift of the LSPR scattering maximum, lambda(max), and makes it possible to detect the presence of only one or a few HRP molecules per particle.

lithography

proteins

peroxidase

nanoparticles

single molecules

ELISA

biosensors

Surface plasmon

resonance

spectra imaging

single particles

biosensor

Författare

Si Chen

Chalmers, Teknisk fysik, Bionanofotonik

Mikael Svedendahl

Chalmers, Teknisk fysik, Bionanofotonik

R. P. Van Duyne

Northwestern University

Mikael Käll

Chalmers, Teknisk fysik, Bionanofotonik

Nano Letters

1530-6984 (ISSN) 1530-6992 (eISSN)

Vol. 11 4 1826-1830

Ämneskategorier

Fysik

Biofysik

DOI

10.1021/nl2006092