title: An inhibitory enzyme electrode for hydrogen sulfide detection.
abstract: An enzymatic biosensing system has been developed to study the capability of ascorbate oxidase (AOx), EC (1.10.3.3), in hydrogen sulfide (H2S) detection, based on the inhibition of AOx activity. The immobilization parameters including glutaraldehyde (GA) concentration and pH were optimized using experimental design. The optimized values of GA concentration and pH were found to be 12.5% (w/w) and 7, respectively, where the enzymatic reaction reached the steady-state level within 55 s. A linear relationship was observed between the decrease in the oxygen concentration and H2S concentration, where H2S concentration is in the range of 1-15 mg/L. Moreover, to investigate the selectivity of the biosensor, a certain H2S concentration (9 mg/L) was used against different ions. The results indicated that Fe(3+) and SO4(-2) ions had no significant (11% error) effect on the H2S detection. The operational stability of the biosensing system was determined in terms of response to H2S concentration, at optimal working conditions. The enzyme electrode could retain 73% of its original sensitivity after this period, which has made it possible for the system to measure H2S with concentrations as low as 0.5 mg/L.
authors.affiliation: Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran; Department of Biochemical Engineering, Science & Research Branch Islamic Azad University, Tehran, Iran.
authors.forename: Neda Zia Mottalebi
authors.initials: NZ
authors.lastname: poor
authors.affiliation: Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran; Department of Biochemical Engineering, Science & Research Branch Islamic Azad University, Tehran, Iran.
authors.forename: Ladan
authors.initials: L
authors.lastname: Baniasadi
authors.affiliation: Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran; Department of Life Science Engineering, Faculty of New sciences and Technologies, University of Tehran, Tehran, Iran.
authors.forename: Maysam
authors.initials: M
authors.lastname: Omidi
authors.affiliation: School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran; Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran. Electronic address: amoabediny@ut.ac.ir.
authors.forename: Ghasem
authors.initials: G
authors.lastname: Amoabediny
authors.affiliation: Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran; Department of Life Science Engineering, Faculty of New sciences and Technologies, University of Tehran, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Yazdian
authors.affiliation: Department of Biochemical Engineering, Science & Research Branch Islamic Azad University, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Attar
authors.affiliation: Department of Jahad Daneshghahi, College of Engineering, University of Tehran, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Heydarzadeh
authors.affiliation: Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran; Department of Life Science Engineering, Faculty of New sciences and Technologies, University of Tehran, Tehran, Iran.
authors.forename: Ashraf Sadat Hatamian
authors.initials: AS
authors.lastname: Zarami
authors.affiliation: Shahid Sadoughi University of Medical Sciences, Yazd, Iran; Biotechnology Research Center, International Campus, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Sheikhha
mesh_terms: D001204:Ascorbate Oxidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D001205:Ascorbic Acid; D015374:Biosensing Techniques / Q000379:methods; D002138:Calibration; D002412:Cations; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005976:Glutaral; D006862:Hydrogen Sulfide / Q000032:analysis* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D009757:Nylons; D009994:Osmolar Concentration; D010100:Oxygen; D013379:Substrate Specificity
chemical_list: D002412:Cations; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D009757:Nylons; D001204:Ascorbate Oxidase; D001205:Ascorbic Acid; D010100:Oxygen; D005976:Glutaral; D006862:Hydrogen Sulfide
keywords: Ascorbate oxidase (AOx); Dissolved oxygen; Enzymatic biosensors; Enzyme activity; Hydrogen sulfide (H(2)S); Immobilized enzymes