title: Use of one- and two-mediator systems for developing a BOD biosensor based on the yeast Debaryomyces hansenii.
abstract: We investigated the use of one- and two-mediator systems in amperometric BOD biosensors (BOD, biochemical oxygen demand) based on the yeast Debaryomyces hansenii. Screening of nine mediators potentially capable of electron transfer - ferrocene, 1,1'-dimethylferrocene, ferrocenecarboxaldehyde, ferroceneacetonitrile, neutral red, 2,6-dichlorophenolindophenol, thionine, methylene blue and potassium ferricyanide - showed only ferrocene and neutral red to be efficient electron carriers for the eukaryotes studied. Two-mediator systems based on combinations of the investigated compounds were used to increase the efficiency of electron transfer. The developed two-mediator biosensors exceeded their one-mediator analogs by their characteristics. The most preferable two-mediator system for developing a BOD biosensor was a ferrocene-methylene blue combination that ensured a satisfactory long-time stability (43 days), selectivity, sensitivity (the lower limit of the determined BOD5concentrations, 2.5mg О2/dm3) and speed (assay time for one sample, not greater than 10min) of BOD determination. Analysis of water samples showed that the use of a ferrocene-methylene blue two-mediator system and the yeast D. hansenii enabled registration of data that highly correlated with the results of the standard method (R=0.9913).
authors.affiliation: Tula State University, 92 Lenin Prosp., Tula, 300012, Russia.
authors.forename: A S
authors.initials: AS
authors.lastname: Zaitseva
authors.affiliation: Tula State University, 92 Lenin Prosp., Tula, 300012, Russia.
authors.forename: V A
authors.initials: VA
authors.lastname: Arlyapov
authors.affiliation: Tula State University, 92 Lenin Prosp., Tula, 300012, Russia.
authors.forename: N Yu
authors.initials: NY
authors.lastname: Yudina
authors.affiliation: Tula State University, 92 Lenin Prosp., Tula, 300012, Russia.
authors.forename: S V
authors.initials: SV
authors.lastname: Alferov
authors.affiliation: Tula State University, 92 Lenin Prosp., Tula, 300012, Russia; G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 5 Prosp. Nauki, Pushchino, Moscow Region, 142290, Russia. Electronic address: anatol@ibpm.pushchino.ru.
authors.forename: A N
authors.initials: AN
authors.lastname: Reshetilov
mesh_terms: D057919:Biological Oxygen Demand Analysis / Q000379:methods*; D015374:Biosensing Techniques / Q000379:methods*; D055165:Debaryomyces / Q000378:metabolism*; D004579:Electron Transport; D005296:Ferrous Compounds / Q000378:metabolism; D007202:Indicators and Reagents / Q000378:metabolism; D000075163:Metallocenes; D008751:Methylene Blue / Q000378:metabolism; D009499:Neutral Red / Q000378:metabolism; D014867:Water / Q000032:analysis
chemical_list: D005296:Ferrous Compounds; D007202:Indicators and Reagents; D000075163:Metallocenes; D014867:Water; D009499:Neutral Red; D008751:Methylene Blue; C004998:ferrocene
keywords: BOD (biochemical oxygen demand); BOD(5); Biosensor; Mediator; Yeast Debaryomyces hansenii