Open AccessSurface-enhanced Raman Scattering for Immunoassay Based on the Biocatalytic Production of Silver Nanoparticles
Author(s) -
Jiwei Chen,
Yan Luo,
Yi Liang,
JianHui Jiang,
GuoLi Shen,
RuQin Yu
Publication year - 2009
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.2116/analsci.25.347
Subject(s) - ascorbic acid , chemistry , detection limit , substrate (aquarium) , immunoassay , raman scattering , silver nanoparticle , nanoparticle , raman spectroscopy , colloidal gold , linear range , chromatography , nuclear chemistry , nanotechnology , materials science , oceanography , physics , food science , antibody , optics , immunology , biology , geology
We have reported on a novel enzyme immunoassay method for the detection of protein using biocatalytic silver nanoparticles as an enhanced substrate based on surface-enhanced Raman scattering (SERS). First, ascorbic acid was converted from ascorbic acid 2-phosphate by alkaline phosphatase immobilized on polystyrene microwells after a typical sandwich immunoreaction. Then Ag(I) ions were reduced to silver nanoparticles by the obtained ascorbic acid, which would result in a SERS signal when Raman dyes were absorbed. Using human IgG as a model protein, a wide linear dynamic range (1 to 100 ng ml(-1)) was reached with a low detection limit (0.02 ng ml(-1)) under the optimized assay conditions. Moreover, the production of an enhanced substrate was chosen as the signaling element in this method, which demonstrates a new way for SERS-based quantitative detection. These results suggest that the application of SERS enhanced by biocatalytic production of metal nanopaticles holds a promising potential for a sensitive immunoassay.