Antibodies Irreversibly Adsorb to Gold Nanoparticles
and Resist Displacement by Common Blood Proteins
Guadalupe Ruiz
Nicki Ryan
Kylie Rutschke
Olatunde Awotunde
Jeremy D. Driskell
10.1021/acs.langmuir.9b01900.s001
https://acs.figshare.com/articles/journal_contribution/Antibodies_Irreversibly_Adsorb_to_Gold_Nanoparticles_and_Resist_Displacement_by_Common_Blood_Proteins/9238454
Gold nanoparticles
(AuNPs) functionalized with proteins to impart
desirable surface properties have been developed for many nanobiotechnology
applications. A strong interaction between the protein and nanoparticle
is critical to the formation of a stable conjugate to realize the
potential of these emerging technologies. In this work, we examine
the robustness of a protein layer adsorbed onto gold nanoparticles
while under the stress of a physiological environment that could potentially
lead to protein exchange on the nanoparticle surface. The adsorption
interaction of common blood plasma proteins (transferrin, human serum
albumin, and fibrinogen) and anti-horseradish peroxidase antibody
onto AuNPs is investigated by nanoparticle tracking analysis. Our
data show that a monolayer of protein is formed at saturation for
each protein, and the maximum size increase for the conjugate, relative
to the AuNP core, correlates with the protein size. The binding affinity
of each protein to the AuNP is extracted from a best fit of the adsorption
isotherm to the Hill equation. The antibody displays the greatest
affinity (<i>K</i><sub>d</sub> = 15.2 ± 0.8 nM) that
is ∼20–65 times stronger than the affinity of the other
plasma proteins. Antibody–AuNP conjugates were prepared, purified,
and suspended in solutions of blood plasma proteins to evaluate the
stability of the antibody layer. An enzyme-mediated assay confirms
that the antibody–AuNP interaction is irreversible, and the
adsorbed antibody resists displacement by the plasma proteins. This
work provides insight into the capabilities and potential limitations
of antibody–AuNP-enabled technologies in biological systems.
2019-08-02 20:44:55
Common Blood Proteins Gold nanoparticles
blood plasma proteins
plasma proteins
anti-horseradish peroxidase antibody
Antibodies Irreversibly Adsorb