title: A sepiolite modified conducting polymer based biosensor.
abstract: A conducting polymer modified with sepiolite was utilized in the construction of a highly sensitive and fast amperometric cholesterol biosensor. In this study a monomer; (10,13-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)dibenzo[a,c]phenazine (PHED)) was synthesized and then its polymer was coated on a graphite electrode by electropolymerization to obtain a matrix for enzyme immobilization. Cholesterol oxidase was immobilized onto polymer coated electrode by adsorption technique. Sepiolite was introduced for a successful immobilization of the cholesterol oxidase. Immobilized enzyme kinetic parameters (KM(app), Imax) were evaluated by Michaelis-Menten kinetics and calculated as 0.031 mM and 6.06 μA, respectively. LOD and sensitivity were estimated as 0.36 μM and 1.64 mA/mMcm(2). Characterization of designed biosensor was done to examine the effect of various factors such as enzyme amount, optimum pH and shelf-life. A novel accurate and inexpensive cholesterol biosensor was developed for the determination of total cholesterol in food samples.
authors.affiliation: Department of Chemistry, Middle East Technical University, Ankara 06800, Turkey. Electronic address: saniyesoylemez@gmail.com.
authors.forename: Saniye
authors.initials: S
authors.lastname: Soylemez
authors.affiliation: Department of Biotechnology, Middle East Technical University, Ankara 06800, Turkey. Electronic address: fulyaekiz@gmail.com.
authors.forename: Fulya Ekiz
authors.initials: FE
authors.lastname: Kanik
authors.affiliation: Chemical Engineering, Delft University of Technology, The Netherlands. Electronic address: s.tarkuc@tudelft.nl.
authors.forename: Simge
authors.initials: S
authors.lastname: Tarkuc
authors.affiliation: Institute of Science and Technology, Department of Advanced Technologies, Gazi University, 06000, Turkey. Electronic address: y.udum@gazi.edu.tr.
authors.forename: Yasemin Arslan
authors.initials: YA
authors.lastname: Udum
authors.affiliation: Department of Chemistry, Middle East Technical University, Ankara 06800, Turkey; Department of Biotechnology, Middle East Technical University, Ankara 06800, Turkey; Department of Polymer Science and Technology, Middle East Technical University, Ankara 06800, Turkey; The Center for Solar Energy Research and Application (GUNAM), Middle East Technical University, Ankara 06800, Turkey. Electronic address: toppare@metu.edu.tr.
authors.forename: Levent
authors.initials: L
authors.lastname: Toppare
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D002784:Cholesterol / Q000032:analysis / Q000737:chemistry; D002789:Cholesterol Oxidase / Q000378:metabolism; D004553:Electric Conductivity; D005502:Food; D006863:Hydrogen-Ion Concentration; D017633:Magnesium Silicates / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D011551:Pseudomonas fluorescens / Q000201:enzymology; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D017633:Magnesium Silicates; D011108:Polymers; D002784:Cholesterol; C001671:magnesium trisilicate; D002789:Cholesterol Oxidase
keywords: Amperometric biosensor; Cholesterol biosensor; Cholesterol oxidase; Clay; Conducting polymer; Sepiolite