title: Investigating the effect of design parameters on the response time of a highly sensitive microbial hydrogen sulfide biosensor based on oxygen consumption.
abstract: A novel hydrogen sulfide microbial biosensor was developed based on investigating the influence of four design parameters: cell concentration, immobilization bed type, hydrogen sulfide concentration, and geometrical shape of the biosensor. Thiobacillus thioparus was used as the recognition element and it was immobilized on sodium alginate as well as agarose bed. The results were optimized by the application of statistical optimization software based on response time of the system. Oxygen reduction was considered as the detection sign. Sodium alginate solution with a concentration of 2.3% (w/v) and optical density of 10 at 605 nm was found as the optimum conditions for immobilization with response time of 72s . Optimum response time of immobilized T. thioparus on agarose was also found equal to 120 s at agarose concentration of 1.2% (w/v) and optical density of 10.83. Performance of the biosensor in different temperatures, pH and agitation speeds was also analyzed. The designed biosensor could detect concentrations of hydrogen sulfide as low as 0.5 ppm. T. thioparus could retain 99% of the original activity in both systems, after ten days passing the fabrication. A fractal analysis was also done theoretically to investigate the diffusion of oxygen in immobilized cells which showed a satisfactory value of oxygen take up by the immobilized cells.
authors: Department of Biochemical and Pharmaceutical Engineering, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran; Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran.
authors: Amin
authors: A
authors: Vosoughi
authors: Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran; Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran, Iran.
authors: Fatemeh
authors: F
authors: Yazdian
authors: Department of Biochemical and Pharmaceutical Engineering, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran; Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran. Electronic address: amoabediny@ut.ac.ir.
authors: Ghassem
authors: G
authors: Amoabediny
authors: Department of Chemical Engineering, Sharif University of Technology, P.O. Box 11365-11155, Tehran, Iran.
authors: Maziar
authors: M
authors: Hakim
mesh_terms: D001681:Biological Assay / Q000295:instrumentation*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006862:Hydrogen Sulfide / Q000032:analysis* / Q000494:pharmacology; D008954:Models, Biological; D010092:Oximetry / Q000295:instrumentation; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013855:Thiobacillus / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: D010100:Oxygen; D006862:Hydrogen Sulfide
keywords: Agarose; Design parameters; Hydrogen sulfide; Response time; Sodium alginate; Thiobacillus thioparus