title: Quantitative determination of Escherichia coli based on the electrochemical measurement of bacterial catalase activity using H2O2-selective organic/inorganic-hybrid sol-gel film-modified Pt electrode.
abstract: Quantitative determination of Escherichia coli (E. coli) concentration was achieved by measuring the intrinsic catalase activity of E. coli using novel H2O2-selective organic/inorganic-hybrid sol-gel film-modified platinum (Pt) wire electrode. This hybrid sol-gel film is composed of three kinds of organosilanes and two biopolymers (i.e., chitosan and bovine serum albumin), and exhibited an excellent permselectivity toward H2O2 based on a size-exclusive mechanism. The steady-state anodic current for 100 [xmol/L H2O2 at +0.6 V (vs. Ag/AgCl) in 0.1 mol/L phosphate buffer (pH 6.5) solution was apparently diminished by the addition of E. coli samples, due to the decomposition of H2O2 by intrinsic catalase activity of E. coli. The time-dependent decrease in current (-AI/At) was significantly dependent on the E. coli concentration. The -AI/At was enhanced by the permeabilization pretreatment of E. coli samples with the mixed solution of polymyxin B and lysozyme. This H2O2-selective organic/inorganic-hybrid sol-gel film-modified platinum (Pt) wire electrode allowed quantitative determination of E. coli concentration ranging from 10(6) to 10(9) CFU/mL within 30 min. This method required no label and complicated procedure, and allowed rapid, simple and cost-effective quantitative electrochemical determination of catalase-positive bacteria.
authors.affiliation: Department of Life Science and Green Chemistry, Faculty of Engineering, Saitama Institute of Technology, Fukaya, Saitama 369-0293, Japan; Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Instite of Technology, Fukaya, Saitama 369-0293, Japan. hasebe@sit.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hasebe
authors.affiliation: Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Instite of Technology, Fukaya, Saitama 369-0293, Japan.
authors.forename: Michiru
authors.initials: M
authors.lastname: Fukuzawa
authors.affiliation: Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Instite of Technology, Fukaya, Saitama 369-0293, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Matsuhisa
mesh_terms: D002374:Catalase / Q000378:metabolism*; D004560:Electricity; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004926:Escherichia coli / Q000166:cytology* / Q000201:enzymology; D005782:Gels; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007287:Inorganic Chemicals / Q000737:chemistry*; D009113:Muramidase / Q000494:pharmacology; D009930:Organic Chemicals / Q000737:chemistry*; D010539:Permeability; D010984:Platinum / Q000737:chemistry*; D011112:Polymyxin B / Q000494:pharmacology; D013997:Time Factors
chemical_list: D005782:Gels; D007287:Inorganic Chemicals; D009930:Organic Chemicals; D010984:Platinum; D006861:Hydrogen Peroxide; D002374:Catalase; D009113:Muramidase; D011112:Polymyxin B