Homogeneous, competitive fluorescence quenching immunoassay based on gold nanoparticle/polyelectrolyte coated latex particles

Abstract

This study reports a homogeneous and competitive fluorescence quenching immunoassay based on gold nanoparticle/polyelectrolyte (AuNP/PE) coated latex particles prepared by the layer-by-layer (LbL) technique. First, the resonant energy transfer from a layer of fluorescent PEs to AUNP in LbL assembled films on planar substrates was investigated. The quenching efficiency (QE) for the planar films depended on the cube of the distance between the two layers. A QE of 50% was achieved at a distance of ca. 15 nm, indicating that the AUNP/PE system is suitable for detecting binding/release events for antibodies. A homogeneous, competitive binding immunoassay for biotin was designed based on AuNP/PE-c..