Enzyme-Linked Immunosorbent Assay to Quantify Targeting Molecules on Nanoparticles.

Molecular targeting presents a promising means of improving the specificity of cancer therapeutics, increasing accumulation at the cancer site and limiting off-target effects. These targeting schemes can be applied to nanoparticle-based treatments to further enhance their anticancer efficacy. Here, we describe methods to conjugate antibodies to silica-gold nanoshells and to quantify the resulting antibody content on the nanoparticles using a solution-based enzyme-linked immunosorbent assay (ELISA). Although we will be using anti-EGFR (epidermal growth factor receptor) antibodies conjugated to gold-silica nanoshells as a model system, this method is adaptable to quantify a range of targeting antibodies and proteins on various types of nanoparticles.