title: Design of novel electron transfer mediators based on indophenol derivatives for lactate sensor.
abstract: Novel indophenol derivatives which have limited solubility in water solution functioned as excellent electron-transfer mediators for lactate oxidase and a lactate sensor, showing good sensor performance, including a high sensitivity and good durability. These less water-soluble mediators were prepared by the O-alkylation or acylation of indophenols in order to prevent the mediator being leached from the sensor. Consequently the characteristic substituent effects of indophenol derivatives were found to be follows, (1) modification of the phenolic OH group improved sensor durability; (2) the presence of chloride groups at the 2,6-positions of the phenol ring improved the sensitivity of the sensor; (3) the introduction of substituents at the quinoide moiety led to a deterioration in durability. A mediator based lactate sensor using these derivatives was found to be nearly independent of oxygen concentration, showed a low level of interference effect, and a quite long durability.
authors.affiliation: Ciba Specialty Chemicals. K. K. 10-66, Miyukicho, Takarazuka, 665-8666, Hyogo, Japan. keisuke.hirano@cibasc.com
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hirano
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamato
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kunimoto
authors.forename: Masaki
authors.initials: M
authors.lastname: Ohwa
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism; D019544:Equipment Failure Analysis; D007215:Indophenol / Q000031:analogs & derivatives* / Q000737:chemistry; D019344:Lactic Acid / Q000032:analysis*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D019344:Lactic Acid; D007215:Indophenol; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase; D010100:Oxygen