title: Metal-enhanced immunoassays.
abstract: The surface-confined assay format is one of the most convenient detection formats used in many immunoassays. Fluorescence emission from monolayers of dyes requires a strong excitation and good detection system. Such samples are susceptible to artifacts due to background fluorescence from substrates. We demonstrate that using silver nanostructures deposited on the slide substrate can significantly enhance measured fluorescence, reduce unwanted background and increase photostability of the used probes. Using thin layers of polymer doped with fluorescein, we tested two nanostructures--silver island films (SIFs) deposited on glass slides and self-assembled colloidal structures (SACS) deposited on thin silver film. The SACS surfaces show extraordinary fluorescence enhancements: over 100-folds in hot spots. We applied these surfaces for enhanced Alexa488 model immunoassay.
authors.affiliation: Center for Commercialization of Fluorescence Technologies, University of North Texas Health Science Center, Fort Worth, TX, USA. igryczyn@hcs.unt.edu
authors.forename: Ignacy
authors.initials: I
authors.lastname: Gryczynski
authors.forename: Rafal
authors.initials: R
authors.lastname: Luchowski
authors.forename: Evgenia G
authors.initials: EG
authors.lastname: Matveeva
authors.forename: Tanya
authors.initials: T
authors.lastname: Shtoyko
authors.forename: Pabak
authors.initials: P
authors.lastname: Sarkar
authors.forename: Julian
authors.initials: J
authors.lastname: Borejdo
authors.forename: Irina
authors.initials: I
authors.lastname: Akopova
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Gryczynski
mesh_terms: D005455:Fluorescent Antibody Technique / Q000379:methods; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D012834:Silver / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D008670:Metals; D012834:Silver