title: [Catechol biosensor based on immobilizing laccase to modified core-shell magnetic nanoparticles supported on carbon paste electrode].
abstract: A catechol biosensor was developed and used to analyze compost extracts based on the immobilization of laccase on the surface of modified magnetic core-shall (Fe3O4-SiO2) nanoparticles. Laccase was convalently immobilized on the magnetic nanoparticles by glutaraldehyde, which were modified with amino groups on its surface. The resulting magnetic bio-nanoparticles were attached to the surface of carbon paste electrode with the help of a permanent magnet to determine catechol. The immobilization matrix provided a good microenvironment for retaining the bioactivity of laccase. The linear range for catechol determination was 7.5 x 10(-7)-2.75 x 10(-4) mol/L, with a detection limit of 7.5 x 10(-7) mol/L. The detection current reached 95% of the steady-state current within about 70 s. Catechol concentration in compost extracts were determined by laccase biosensor and HPLC, with approximately the same result.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China. ezhangyi123@yahoo.com.cn
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guang-ming
authors.initials: GM
authors.lastname: Zeng
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.forename: Hong-yan
authors.initials: HY
authors.lastname: Yu
authors.forename: Jian-bing
authors.initials: JB
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry*; D002396:Catechols / Q000032:analysis*; D004563:Electrochemistry; D004566:Electrodes; D004574:Electromagnetic Fields; D004800:Enzymes, Immobilized / Q000378:metabolism; D042845:Laccase / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry
chemical_list: D002396:Catechols; D004800:Enzymes, Immobilized; D002244:Carbon; D042845:Laccase; C034221:catechol