title: A novel protocol for covalent immobilization of thionine on glassy carbon electrode and its application in hydrogen peroxide biosensor.
abstract: A novel protocol for effectively covalent immobilization of thionine (Th) was proposed, which was based on Schiff-base reaction between -NH(2) of Th and -COH which was in situ generated on glassy carbon electrode (GCE) via simple potentiostatic activation in diluted nitric acid. GCE pretreated by potentiostatic activation possessed CHO-riched surface and microporous structure with high distribution density of electron transfer sites, and thus it became a good candidate for effective immobilization of Th through imine bond with high stability. The application of the resulting Th modified electrode in hydrogen peroxide biosensor was also investigated and it exhibited rapid response to H(2)O(2) within 3s. The linear calibration ranged from 5.0x10(-7) to 5.8x10(-3)M with a detection limit of 1.0x10(-7)M. The effective immobilization of Th on potentiostatically activated GCE surface has deep significance in mediator immobilization, on which further researches based are under way.
authors.affiliation: Key Laboratory of Marine Sediment and Environmental Geology of State Oceanic Administration, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, PR China.
authors.forename: Xingyong
authors.initials: X
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Hongjun
authors.initials: H
authors.lastname: Yu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005898:Glass / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D010640:Phenothiazines / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010640:Phenothiazines; D002244:Carbon; D006861:Hydrogen Peroxide; C009469:thionine