Asymmetrically Functionalized Antibody-Gold Nanoparticle Conjugates to Form Stable Antigen-Assembled Dimers.
Biomolecular assays based on the aggregation of modified gold nanoparticles (AuNPs) have been developed to provide low detection limits and rapid results with a simple one-step, wash-free procedure. However, a relatively narrow dynamic range, low sensitivity, and poor precision due to time-sensitive readout limit the application of these assay platforms. In this work we synthesized asymmetrically functionalized antibody-AuNP conjugates that are rationally designed to overcome the limitations of aggregation-based immunoassays. Solid-phase synthesis was used to chemically passivate the majority of the AuNP surface and restrict antibody immobilization into a small area of the AuNP surface. These asymmetric conjugates assembled into dimers with the addition of antigen and were stable for over 24 h. In contrast, conventional antibody-AuNP conjugates which are symmetrically modified with antibody assembled into large aggregates that continuously increased in size with the addition of target antigen. These results suggest that asymmetric antibody-AuNP conjugates have the potential to significantly improve the analytical performance of aggregation-based immunoassays.
Department of Chemistry, Illinois State University , Normal, Illinois 61790, United States.
Alexandra
A
Mandl
Department of Chemistry, Illinois State University , Normal, Illinois 61790, United States.
Seth L
SL
Filbrun
Department of Chemistry, Illinois State University , Normal, Illinois 61790, United States.
Jeremy D
JD
Driskell
D000906:Antibodies / Q000737:chemistry*; D019281:Dimerization; D006046:Gold / Q000737:chemistry*; D018796:Immunoconjugates / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*
D000906:Antibodies; D018796:Immunoconjugates; D006046:Gold