Synthesis and bioconjugation of gold nanoparticles as potential molecular probes for light-based imaging techniques

Abstract

We have synthesized and characterized gold nanoparticles (spheres and rods) with optical extinction bands withinthe "optical imaging window." The intense plasmon resonant driven absorption and scattering peaks of these nanoparticlesmake them suitable as contrast agents for optical imaging techniques. Further, we have conjugated these gold nanoparticlesto a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells. The bioconjugationprotocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions ofthe antibody and the gold surface. We discuss various aspects of the synthesis and bioconjugation protocols and thecharacterization results of the functionalized nanoparticles. Some proposed applications of these potential molecularprobes in the field of biomedical imaging are also discussed.