title: Sulfamethazine detection with direct-binding optical waveguide lightmode spectroscopy-based immunosensor.
abstract: A direct-binding optical waveguide lightmode spectroscopy-based immunosensor detecting sulfamethazine (SMZ) was prepared, followed by the measurement of its specificity and sensitivity. System construction was undertaken with a peristaltic pump, an injector and the main unit comprising a sensor holder, two signal-harvesting photodiodes, a beam mirror, shutter and He-Ne laser source emitting a monochrome light (λ=632.8nm), plus a PC. Antibody immobilization was performed in situ by covalent binding of an anti-SMZ antibody over the surface of a glutaraldehyde-activated 3-aminopropyltriethoxysilane-treated sensor chip. The reaction buffer for the system was 4mM Tris-HCl (pH 7.2) that showed a medium surface coverage and stable baseline. Sensor response was quite specific to antibody-antigen complexation, as judged from no sensor response caused by bovine serum albumin immobilization. The sensor responses according to SMZ concentrations from 10(-8) to 10(-2)M increased linearly in a semi-logarithmic scale, with the limit of detection of 10(-8)M. The immunosensor was favorably reusable for SMZ screening.
authors.affiliation: Food Function Research Division, Korea Food Research Institute, San 46-1, Baekhyun-dong, Bundang-gu, Songnam-si, Kyonggi-do 463-746, Republic of Korea. Electronic address: k9130sen@hanmail.net.
authors.forename: Namsoo
authors.initials: N
authors.lastname: Kim
authors.affiliation: Food Function Research Division, Korea Food Research Institute, San 46-1, Baekhyun-dong, Bundang-gu, Songnam-si, Kyonggi-do 463-746, Republic of Korea.
authors.forename: Dong-Kyung
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Food Function Research Division, Korea Food Research Institute, San 46-1, Baekhyun-dong, Bundang-gu, Songnam-si, Kyonggi-do 463-746, Republic of Korea; Department of Biotechnology, Chung-Ang University, Ansung-si, Kyonggi-do 456-756, Republic of Korea.
authors.forename: Woo-Yeon
authors.initials: WY
authors.lastname: Kim
keywords: Optical waveguide lightmode spectroscopy-based immunosensor; Specificity and sensitivity; Sulfamethazine detection