title: Functionalized-graphene modified graphite electrode for the selective determination of dopamine in presence of uric acid and ascorbic acid.
abstract: Graphene is chemically synthesized by solvothermal reduction of colloidal dispersions of graphite oxide. Graphite electrode is modified with functionalized-graphene for electrochemical applications. Electrochemical characterization of functionalized-graphene modified graphite electrode (FGGE) is carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The behavior of FGGE towards ascorbic acid (AA), dopamine (DA) and uric acid (UA) has been investigated by CV, differential pulse voltammetry (DPV) and chronoamperommetry (CA). The FGGE showed excellent catalytic activity towards electrochemical oxidation of AA, DA and UA compared to that of the bare graphite electrode. The electrochemical oxidation signals of AA, DA and UA are well separated into three distinct peaks with peak potential separation of 193mv, 172mv and 264mV between AA-DA, DA-UA and AA-UA respectively in CV studies and the corresponding peak potential separations in DPV mode are 204mv, 141mv and 345mv. The FGGE is successfully used for the simultaneous detection of AA, DA and UA in their ternary mixture and DA in serum and pharmaceutical samples. The excellent electrocatalytic behavior of FGGE may lead to new applications in electrochemical analysis.
authors.affiliation: Chemistry Research Centre, S.S.M.R.V. Degree College, Jayanagar, Bangalore-560041, India.
authors.forename: Malledevaru
authors.initials: M
authors.lastname: Mallesha
authors.forename: Revanasiddappa
authors.initials: R
authors.lastname: Manjunatha
authors.forename: C
authors.initials: C
authors.lastname: Nethravathi
authors.forename: Gurukar Shivappa
authors.initials: GS
authors.lastname: Suresh
authors.forename: Michael
authors.initials: M
authors.lastname: Rajamathi
authors.forename: Jose Savio
authors.initials: JS
authors.lastname: Melo
authors.forename: Thimmappa Venkatarangaiah
authors.initials: TV
authors.lastname: Venkatesha
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis* / Q000097:blood / Q000652:urine; D015374:Biosensing Techniques / Q000379:methods; D056246:Chemistry, Analytic; D058266:Dielectric Spectroscopy / Q000379:methods*; D004298:Dopamine / Q000032:analysis* / Q000097:blood / Q000652:urine; D055664:Electrochemical Techniques; D004566:Electrodes; D004867:Equipment Design; D006108:Graphite / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D011199:Potentiometry / Q000295:instrumentation*; D014527:Uric Acid / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D014527:Uric Acid; D006108:Graphite; D001205:Ascorbic Acid; D004298:Dopamine