title: Signal amplification by enzymatic reaction in an immunosensor based on localized surface plasmon resonance (LSPR).
abstract: An enzymatic reaction was employed as a means to enhance the sensitivity of an immunosensor based on localized surface plasmon resonance (LSPR). The reaction occurs after intermolecular binding between an antigen and an antibody on gold nano-island (NI) surfaces. For LSPR sensing, the gold NI surface was fabricated on glass substrates using vacuum evaporation and heat treatment. The interferon-γ (IFN-γ) capture antibody was immobilized on the gold NIs, followed by binding of IFN-γ to the antibody. Subsequently, a biotinylated antibody and a horseradish peroxidase (HRP) conjugated with avidin were simultaneously introduced. A solution of 4-chloro-1-naphthol (4-CN) was then used for precipitation; precipitation was the result of the enzymatic reaction catalyzed the HRP on gold NIs. The LSPR spectra were obtained after each binding process. Using this method, the enzyme-catalyzed precipitation reaction on the gold NI surface was found to effectively amplify the change in the signal of the LSPR immunosensor after intermolecular binding.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. t2taehan@gmail.com
authors.forename: Tae-Han
authors.initials: TH
authors.lastname: Lee
authors.forename: Seung-Woo
authors.initials: SW
authors.lastname: Lee
authors.forename: Ji-Ae
authors.initials: JA
authors.lastname: Jung
authors.forename: Junhyoung
authors.initials: J
authors.lastname: Ahn
authors.forename: Min-Gon
authors.initials: MG
authors.lastname: Kim
authors.forename: Yong-Beom
authors.initials: YB
authors.lastname: Shin
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D006801:Humans; D007124:Immunoenzyme Techniques / Q000295:instrumentation*; D007371:Interferon-gamma / Q000032:analysis / Q000378:metabolism; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods
chemical_list: D055910:Antibodies, Immobilized; D006046:Gold; D007371:Interferon-gamma