Protein functionalized gold nanoparticles (AuNPs) have been exploited in various domains of science such as drug deliver, biosensing, immunoassay and environmental sensors, due to their optical properties and intriguing surface chemistry. These emerging technologies require engineered surface chemistry to control the orientation, surface coverage, and structure of the adsorbed protein to maximize function. Many procedures have been used to effectively immobilize antibodies onto gold nanoparticles; however, the sensitivity of these immobilized antibodies to target antigen or binding sites is often limited due to improper orientation of the antibodies. There is some evidence that the surface charge of antibodies is responsible for controlling the orientation upon adsorption to gold nanoparticles. Here, we chemically modified antibody to investigate the effect of protein surface charge and chemistry on adsorption to AuNPs. Chemical modification of antibodies by reacting with NHS acrylic acid, acrylate the lysine residues consequently controlling the surface charge of the antibodies and impacting the orientation. In this proceeding, novel analytical techniques are utilized to confirm chemical modification of the antibody and fully characterize the modified antibody with respect to charge and function. Dynamic light scattering, fluorescence, nanoparticle tracking analysis, and other analytical strategies are used to study the adsorption dynamics as well as the orientation of these charge modified antibodies on AuNPs. These fundamental investigations to elucidate the mechanism of protein-AuNP adsorption will lead to optimized bioconjugates that are necessary to realize the full potential of AuNP-enabled nanobiotechnologies.

Adsorption behavior of chemically/charged modified antibody on gold nanoparticles

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.