A label-free immunoassay based upon localized surface plasmon resonance of gold nanorods.
Robust gold nanorod substrates were fabricated for refractive index sensing based on localized surface plasmon resonance (LSPR). The substrate sensitivity was 170 nm/RIU with a figure of merit of 1.3. To monitor biomolecular interactions, the nanorod surfaces were covered with a self-assembled monolayer and conjugated to antibodies by carbodiimide cross-linking. Interactions with a specific secondary antibody were monitored through shifts in the LSPR spectral extinction peak. The resulting binding rates and equilibrium constant were in good agreement with literature values for an antibody-antigen system. The nanorod LSPR sensors were also shown to be sensitive and specific. These results demonstrate that given a sufficiently stable nanoparticle substrate with a well defined chemical interface, LSPR sensing yields similar results to the surface plasmon resonance technique, yet with much simpler instrumentation.
Mayer
Kathryn M
KM
Department of Physics & Astronomy, Rice University, Houston, Texas 77005, USA.
Lee
Seunghyun
S
Liao
Hongwei
H
Rostro
Betty C
BC
Fuentes
Amaris
A
Scully
Peter T
PT
Nehl
Colleen L
CL
Hafner
Jason H
JH
D015374:Biosensing Techniques / Q000379:methods*; D003460:Crystallization / Q000379:methods; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013194:Staining and Labeling; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
D046911:Macromolecular Substances; C009495:titanium dioxide; D006046:Gold; D014025:Titanium