Silver nanoparticle enhanced immunoassays: one step real time kinetic assay for insulin in serum.

Silver nanoparticle enhanced fluorescence is introduced as an alternative method to surface plasmon resonance techniques for real time monitoring of biorecognitive interactions or immunoassays. This method relies on the phenomenon that an electromagnetic near field is generated upon illumination on the surface of silver nanoparticles. The interaction of this field with nearby fluorophores results in fluorescence enhancement.

Wheat germ agglutinin binds to the epidermal growth factor receptor of artificial Caco-2 membranes as detected by silver nanoparticle enhanced fluorescence.

Purpose: The purpose of this study was to identify one of the ligands that mediate carbohydrate-specific cytoadhesion and cytoinvasion of wheat germ agglutinin (WGA)-containing drug delivery systems.

Methods: The receptor-ligand studies were performed with isolated epidermal growth factor (EGF) receptors as well as biomimetic membranes prepared from Caco-2 and A-431 cells. The binding of fluorescent labeled WGA was detected by the silver nanoparticle enhanced fluorescence technique.

Preparation, characterization and application of artificial Caco-2 cell surfaces in the silver nanoparticle enhanced fluorescence technique.

To approach in vivo conditions during real time monitoring of biorecognitive interactions, biomimetic surfaces were prepared by fusion of purified plasma membrane fractions from Caco-2 cells with self-assembled monolayers attached to silver colloid coated standard microplates. Proper orientation and integrity of the membrane coating was confirmed by binding of fluorescein-labelled wheat germ agglutinin (F-WGA) which interacts with certain carbohydrates of the glycocalyx. Additionally, the competition with the complementary carbohydrate decreased the F-WGA binding to 15%.