TY - JOUR
T1 - A surface plasmon resonance immunosensor for detecting a dioxin precursor using a gold binding polypeptide
AU - Soh, N
AU - Tokuda, T.
AU - Watanabe, T.
AU - Mishima, K.
AU - Imato, T.
AU - Masadome, T.
AU - Asano, Y.
AU - Okutani, S.
AU - Niwa, O.
AU - Brown, Stanley
N1 - Author Keywords: SPR sensor; 2,4-Dichlorophenol; Dioxins; Endocrine disrupting chemicals; Gold binding polypeptide; Protein G
PY - 2003
Y1 - 2003
N2 - A surface plasmon resonance (SPR) based biosensor was developed for monitoring 2,4-dichlorophenol, a known dioxin precursor, using an indirect competitive immunoassay. The SPR sensor was fabricated by immobilizing a gold-thin layer on the surface of an SPR sensor chip with an anti-(2,4-dichlorophenol) antibody using a gold binding polypeptide (GBP) and protein G. The SPR response based on the antigen–antibody reaction in a flow system was measured by injecting a 2,4-dichlorophenol sample solution into the flow system in which the SPR sensor was located. In a direct immunoassay system using the modified sensor chip, no significant SPR angle shift less than 0.001° was observed when a 25 ppm of 2,4-dichlorophenol solution was injected. In order to improve the sensitivity of the SPR sensor, an indirect competitive immunoassay method was used in conjunction with the SPR sensor system using 2,4-dichlorophenol conjugated with bovine serum albumin (BSA). In the competitive assay, a 350 ppm 2,4-dichlorophenol–BSA conjugate solution containing 2,4-dichlorophenol at various concentrations (10–250 ppb) were injected into the SPR sensor system. The sensitivity of this indirect immunoassay was found to be extremely sensitive, compared to the direct one, and a detection limit of 20 ppb was estimated. Verification that the use of GBP for immobilizing the antibody on the sensor chip enhanced the sensitivity to 2,4-dichlorophenol was obtained by comparing the procedure with another modification, in which BSA was used instead of GBP for immobilizing the antibody on the sensor chip. The affinity constant of 2,4-dichlorophenol and its conjugate to the antibody were estimated form the SPR response.
AB - A surface plasmon resonance (SPR) based biosensor was developed for monitoring 2,4-dichlorophenol, a known dioxin precursor, using an indirect competitive immunoassay. The SPR sensor was fabricated by immobilizing a gold-thin layer on the surface of an SPR sensor chip with an anti-(2,4-dichlorophenol) antibody using a gold binding polypeptide (GBP) and protein G. The SPR response based on the antigen–antibody reaction in a flow system was measured by injecting a 2,4-dichlorophenol sample solution into the flow system in which the SPR sensor was located. In a direct immunoassay system using the modified sensor chip, no significant SPR angle shift less than 0.001° was observed when a 25 ppm of 2,4-dichlorophenol solution was injected. In order to improve the sensitivity of the SPR sensor, an indirect competitive immunoassay method was used in conjunction with the SPR sensor system using 2,4-dichlorophenol conjugated with bovine serum albumin (BSA). In the competitive assay, a 350 ppm 2,4-dichlorophenol–BSA conjugate solution containing 2,4-dichlorophenol at various concentrations (10–250 ppb) were injected into the SPR sensor system. The sensitivity of this indirect immunoassay was found to be extremely sensitive, compared to the direct one, and a detection limit of 20 ppb was estimated. Verification that the use of GBP for immobilizing the antibody on the sensor chip enhanced the sensitivity to 2,4-dichlorophenol was obtained by comparing the procedure with another modification, in which BSA was used instead of GBP for immobilizing the antibody on the sensor chip. The affinity constant of 2,4-dichlorophenol and its conjugate to the antibody were estimated form the SPR response.
U2 - 10.1016/S0039-9140(03)00139-5
DO - 10.1016/S0039-9140(03)00139-5
M3 - Journal article
SN - 0039-9140
VL - 60
SP - 733
EP - 745
JO - Talanta: The International Journal of Pure and Applied Analytical Chemistry
JF - Talanta: The International Journal of Pure and Applied Analytical Chemistry
IS - 4
ER -