title: Bienzyme biosensors for glucose, ethanol and putrescine built on oxidase and sweet potato peroxidase.
abstract: Amperometric biosensors for glucose, ethanol, and biogenic amines (putrescine) were constructed using oxidase/peroxidase bienzyme systems. The H(2)O(2) produced by the oxidase in reaction with its substrate is converted into a measurable signal via a novel peroxidase purified from sweet potato peels. All developed biosensors are based on redox hydrogels formed of oxidases (glucose oxidase, alcohol oxidase, or amine oxidase) and the newly purified sweet potato peroxidase (SPP) cross-linked to a redox polymer. The developed electrodes were characterized (sensitivity, stability, and performances in organic medium) and compared with similarly built ones using the 'classical' horseradish peroxidase (HRP). The SPP-based electrodes displayed higher sensitivity and better detection limit for putrescine than those using HRP and were also shown to retain their activity in organic phase much better than the HPR based ones. The importance of attractive or repulsive electrostatic interactions between the peroxidases and oxidases (determined by their isoelectric points) were found to play an important role in the sensitivity of the obtained sensors.
authors.affiliation: Department of Biotechnology, Lund University, P.O. Box 124, SE 221 00, Lund, Sweden.
authors.forename: Jaime
authors.initials: J
authors.lastname: Castillo
authors.forename: Szilveszter
authors.initials: S
authors.lastname: Gáspár
authors.forename: Ivan
authors.initials: I
authors.lastname: Sakharov
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Csöregi
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry; D006631:Amine Oxidase (Copper-Containing) / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004800:Enzymes, Immobilized; D004867:Equipment Design; D000431:Ethanol / Q000032:analysis*; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry; D020100:Hydrogels; D006861:Hydrogen Peroxide / Q000032:analysis*; D027723:Ipomoea batatas / Q000201:enzymology; D009097:Multienzyme Complexes / Q000737:chemistry; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry*; D011700:Putrescine / Q000032:analysis*
chemical_list: D004800:Enzymes, Immobilized; D020100:Hydrogels; D009097:Multienzyme Complexes; D000431:Ethanol; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D005949:Glucose Oxidase; D009195:Peroxidase; D006631:Amine Oxidase (Copper-Containing); D005947:Glucose; D011700:Putrescine