Electroactive Biofilms of Activated Sludge Microorganisms on a Nanostructured Surface as the Basis for a Highly Sensitive Biochemical Oxygen Demand Biosensor
Saniyat Kurbanalieva,
Vyacheslav Arlyapov,
Anna Kharkova,
Roman Perchikov,
Olga Kamanina,
Pavel Melnikov,
Nadezhda Popova,
Andrey Machulin,
Sergey Tarasov,
Evgeniya Saverina,
Anatoly Vereshchagin,
Anatoly Reshetilov
Affiliations
Saniyat Kurbanalieva
Laboratory of Biologically Active Compounds and Biocomposites, Tula State University, Lenin Pr. 92, Tula 300012, Russia
Vyacheslav Arlyapov
Laboratory of Biologically Active Compounds and Biocomposites, Tula State University, Lenin Pr. 92, Tula 300012, Russia
Anna Kharkova
Laboratory of Biologically Active Compounds and Biocomposites, Tula State University, Lenin Pr. 92, Tula 300012, Russia
Roman Perchikov
Laboratory of Biologically Active Compounds and Biocomposites, Tula State University, Lenin Pr. 92, Tula 300012, Russia
Olga Kamanina
Laboratory of Biologically Active Compounds and Biocomposites, Tula State University, Lenin Pr. 92, Tula 300012, Russia
Pavel Melnikov
M. V. Lomonosov Institute of Fine Chemical Technologies, MIREA—Russian Technological University, Prosp. Vernadskogo 86, Moscow 119571, Russia
Nadezhda Popova
Federal State Budgetary Institution of Science Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Leninsky Prosp., 31 k. 4., Moscow 119071, Russia
Andrey Machulin
Institute of Biochemistry and Physiology of Microorganisms of the Russian Academy of Sciences—A Separate Subdivision of the FRC Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Prosp. Science 3, Pushchino 142290, Russia
Sergey Tarasov
Institute of Biochemistry and Physiology of Microorganisms of the Russian Academy of Sciences—A Separate Subdivision of the FRC Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Prosp. Science 3, Pushchino 142290, Russia
Evgeniya Saverina
N. D. Zelinsky Institute of Organic Chemistry, Leninsky Pr. 47, Moscow 119991, Russia
Anatoly Vereshchagin
N. D. Zelinsky Institute of Organic Chemistry, Leninsky Pr. 47, Moscow 119991, Russia
Anatoly Reshetilov
Institute of Biochemistry and Physiology of Microorganisms of the Russian Academy of Sciences—A Separate Subdivision of the FRC Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Prosp. Science 3, Pushchino 142290, Russia
The possibility of the developing a biochemical oxygen demand (BOD) biosensor based on electroactive biofilms of activated sludge grown on the surface of a graphite-paste electrode modified with carbon nanotubes was studied. A complex of microscopic methods controlled biofilm formation: optical microscopy with phase contrast, scanning electron microscopy, and laser confocal microscopy. The features of charge transfer in the obtained electroactive biofilms were studied using the methods of cyclic voltammetry and electrochemical impedance spectroscopy. The rate constant of the interaction of microorganisms with the extracellular electron carrier (0.79 ± 0.03 dm3(g s)−1) and the heterogeneous rate constant of electron transfer (0.34 ± 0.02 cm s−1) were determined using the cyclic voltammetry method. These results revealed that the modification of the carbon nanotubes’ (CNT) electrode surface makes it possible to create electroactive biofilms. An analysis of the metrological and analytical characteristics of the created biosensors showed that the lower limit of the biosensor based on an electroactive biofilm of activated sludge is 0.41 mgO2/dm3, which makes it possible to analyze almost any water sample. Analysis of 12 surface water samples showed a high correlation (R2 = 0.99) with the results of the standard method for determining biochemical oxygen demand.
