title: Measurement of polyphenol oxidase activity using optical waveguide lightmode spectroscopy-based immunosensor.
abstract: Polyphenol oxidase (PPO) is an important quality index during food processing involving heat-treatment and sensitive determination of PPO activity has been a critical concern in the food industry. In this study, a new measurement of PPO activity exploiting an optical waveguide lightmode spectroscopy-based immunosensor is presented using a polyclonal anti-PPO antibody that was immobilized in situ to the surface of a 3-aminopropyltriethoxysilane-treated optical grating coupler activated with glutaraldehyde. When analysed with a purified PPO fraction from potato tubers, a linear relationship was found between PPO activities of 0.0005607-560.7U/mL and the sensor responses obtained. The sensor was applicable to measurement of PPO activity in real samples that were prepared from potato tubers, grapes and Kimchi cabbage, and the analytical results were compared with those obtained by a conventional colorimetric assay measuring PPO activity. When tested for long-term stability, the sensor was reusable up to 10th day after preparation.
authors.affiliation: Research Group of Convergence Technology, Korea Food Research Institute, Seongnam 463-746, Republic of Korea. Electronic address: k9130sen@hanmail.net.
authors.forename: Namsoo
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.
authors.forename: Woo-Yeon
authors.initials: WY
authors.lastname: Kim
mesh_terms: D001937:Brassica / Q000737:chemistry / Q000201:enzymology*; D004156:Catechol Oxidase / Q000032:analysis* / Q000378:metabolism; D007118:Immunoassay / Q000379:methods*; D010940:Plant Proteins / Q000032:analysis* / Q000378:metabolism; D011198:Solanum tuberosum / Q000737:chemistry / Q000201:enzymology*; D013057:Spectrum Analysis / Q000379:methods*; D027843:Vitis / Q000737:chemistry / Q000201:enzymology*
chemical_list: D010940:Plant Proteins; D004156:Catechol Oxidase
keywords: Activity; Immunosensor; Measurement; Optical waveguide lightmode spectroscopy; Polyphenol oxidase