title: Amplified surface plasmon resonance immunosensor for interferon-gamma based on a streptavidin-incorporated aptamer.
abstract: Interferon-gamma (IFN-γ) is associated with susceptibility to tuberculosis, which is a major public health problem worldwide. Although significant progress has been made with regard to the design of enzyme immunoassays for IFN-γ, this assay is still labor-intensive and time-consuming. We therefore designed a DNA aptamer hairpin structure for the detection of IFN-γ with high sensitivity and selectivity. A streptavidin DNA aptamer was incorporated into the IFN-γ binding aptamer probe for the amplified detection of the target molecules. Initially, the probe remained in the inactive configuration. The addition of IFN-γ induced the rearrangement of the aptamer structure, allowing the self-assembly of the active streptavidin aptamer conformation for the streptavidin molecular recognition. Under optimized conditions, the detection limit was determined to be 33 pM, with a dynamic range from 0.3 to 333 nM, both of which were superior to those of corresponding optical sensors. Because combined aptamers are composed of nucleic acids, this optical aptasensor provided the advantages of high sensitivity, simplicity, reusability, and no further labeling or sample pre-treatment.
authors.affiliation: Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Chang
authors.forename: Shenhsiung
authors.initials: S
authors.lastname: Lin
authors.forename: Chung-Han
authors.initials: CH
authors.lastname: Lee
authors.forename: Tsung-Liang
authors.initials: TL
authors.lastname: Chuang
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
authors.forename: Hsin-Chih
authors.initials: HC
authors.lastname: Lai
authors.forename: Chii-Wann
authors.initials: CW
authors.lastname: Lin
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D006801:Humans; D007371:Interferon-gamma / Q000097:blood* / Q000378:metabolism; D057230:Limit of Detection; D009690:Nucleic Acid Conformation; D019809:Streptavidin / Q000378:metabolism*; D013302:Streptomyces / Q000737:chemistry / Q000378:metabolism; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D007371:Interferon-gamma; D019809:Streptavidin