Michael Nash, John Waitumbi, Allan Hoffman, Paul Yager, and Patrick Stayton
The authors present a magnetic-gold nanoparticle antibody-conjugated
detection system. Gold nanoparticles were functionalized with pNIPAAm.
The free carboxyl end of the NIPAAm was conjugated to streptavidin.
Equivalent amounts of biotinylated antibodies, streptavidin-AuNPs, and
pNIPAAm-magnetic NP were added to human plasma samples. With heating,
all NIPAAm collapses to form aggregates of both the gold and magnetic
nanoparticles that can then be separated from supernatent by a magnet.
The enriched mixture was then applyed to a immunoassay to quantify the
amount of antibody successfully captured. They show that using this
system, they can achieve a lower limit of detection with little increase
in background noise. They also demonstrate the versatility of the
system for detecting different biotargets and detecting multiple targets