title: Development of a novel biosensor based on a polypyrrole-dodecylbenzene sulphonate (PPy-DBS) film for the determination of amperometric cholesterol.
abstract: Herein a novel amperometric biosensor based on a conducting polymer with anionic dopant modified electrode was successfully developed for detection of cholesterol. Polypyrrole is deposited on a platinum surface and the sodium dodecylbenzene sulphonate (DBS) ion-doped polypyrrole film was electrochemically prepared by scanning the electrode potential between -0.8 and +0.8 V at a scan rate of 20 mV/s. The present electrochemical biosensor was optimized in terms of working potential, number of cycles, concentrations of monomer, and anionic dopant. Cholesterol oxidase (ChOx) was physically entrapped in PPy-DBS to construct an amperometric cholesterol biosensor. Amperometric determination is based on the electrochemical detection of H2O2generated in the enzymatic reaction of cholesterol. Kinetic parameters, operational and storage stabilities, pH, and temperature dependencies were determined. Km and Imax were calculated as 0.11 μM and 0.967 nM/min, respectively. The operational stability results showed that 90.0% of the response current was retained after 30 activity assays. Morphology of electrodes was characterized by SEM and AFM. Additionally, contact angle measurements were made with 1 μL water of polymer film and enzyme electrode. As a result, the cholesterol biosensor suggested in this study is easy to prepare and is highly cost-effective. This composite (PPy-DBS) can supply a biocompatible and electrochemical microenvironment for immobilization of the enzyme, making this material a good candidate for the fabrication of highly sensitive and selective cholesterol biosensors.
authors: a Department of Chemistry , Institute of Science, Gazi University , Ankara , Turkey.
authors: Bayram Oğuz
authors: BO
authors: Özer
authors: b Department of Chemistry, Faculty of Science , Gazi University , Ankara , Turkey.
authors: Servet
authors: S
authors: Çete
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002784:Cholesterol / Q000032:analysis* / Q000737:chemistry; D002789:Cholesterol Oxidase / Q000737:chemistry / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D013696:Temperature
chemical_list: D001555:Benzene Derivatives; D001557:Benzenesulfonates; D011108:Polymers; D011758:Pyrroles; C041588:dodecylbenzene; C067635:polypyrrole; C001114:dodecylbenzenesulfonic acid; D002784:Cholesterol; D002789:Cholesterol Oxidase
keywords: Biosensor; cholesterol; cholesterol oxidase; polypyrrole; sodium dodecylbenzene sulphonate