Laser-fabricated gold nanoparticles for lateral flow immunoassays

Gold nanoparticles fabricated by pulsed laser ablation are an attractive alternative over those made by chemical reduction, as they offer a more reactive, chemically-bare surface. In this manuscript, we investigate the interactions of these nanoparticles with different classes of antibodies and quantify surface coverage via a fluorescence-based displacement assay. Saturation surface coverage of monoclonal antibodies was found to be almost 2x higher for particles made by pulsed laser ablation (similar to 28 antibodies/particle) as opposed to those made by chemical means (similar to 17 antibodies/particle). This higher coverage translated into similar to 2x better immunoassay sensitivity, demonstrated by a sandwich lateral flow assay for human chorionic gonadotropin. This work highlights the advantages of these pulsed laser-fabricated materials and showcases their unique properties for colorimetric assay development. (C) 2016 Elsevier B.V. All rights reserved.