A Plasmonic Approach to Study Protein Interaction Kinetics through the Dimerization of Functionalized Ag Nanoparticles

Abstract

Understanding the kinetics of protein interactions plays a key role in biology with significant implications for the design of analytical methods for disease monitoring and diagnosis in medical care, research and industrial applications. Herein, we introduce a novel plasmonic approach to study the binding kinetics of protein-ligand interactions following the formation of silver nanoparticles (Ag NPs) dimers by UV-Vis spectroscopy that can be used as probes for antigen detection and quantification. To illustrate and test the method, the kinetics of the prototype biotin-streptavidin (Biot-STV) pair interaction was studied. Controlled aggregates (dimers) of STV functionalized Ag NPs were produced by adding stoichiometric quantities of gliadin-specific biotinylated antibodies (IgG-Biot). The dimerization kinetics was studied in a systematic way as a function of Ag NPs size and at different concentrations of IgG-Biot. The kinetics data have shown to be consistent with a complex reaction mechanism in which only the Ag NPs attached to the IgG-Biot located in a specific STV site are able to form dimers. These results help in elucidating a complex reaction mechanism involved in the dimerization kinetics of functionalized Ag NPs, which can serve as probes in surface plasmon resonance-based bioassays for the detection and quantification of different biomarkers or analytes of interest.

Corrosion Resistance of Graphene oxide/Silver Coatings on Ni–Ti alloy and Expression of IL-6 and IL-8 in Human Oral Fibroblasts

“…Ag nanoparticles (AgNPs) have shown potent antimicrobial properties against several pathogenic bacteria and virus 9,38,39 and they have wide biomedical applications, such as in medical diagnosis, wound sutures, surgical and prosthetic materials [40][41][42] . There have been some issues regarding the cytotoxicity of AgNPs on human cells but the toxicity of AgNPs is only seen at higher concentration 43 .…”