title: Voltammetric discrimination of mandelic acid enantiomers.
abstract: We report a novel electrochemical biosensor for direct discrimination of D- and L-mandelic acid (D- and L-MA) in aqueous medium. The glassy carbon electrode (GCE) surface was modified with reduced graphene oxide (rGO) and γ-globulin (GLOB). Electrochemical characterization of the modified electrodes was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The modified electrode surfaces were also characterized by scanning electron microscopy. Electrochemical response of the prepared electrode (GCE/rGO/GLOB) for discrimination of D- and L-MA enantiomers was investigated by cyclic voltammetry and was compared with bare GCE in the concentration range of 2 to 10 mM. Whereas the bare GCE showed no electrochemical response for the MA enantiomers, the GCE/rGO/GLOB electrode exhibited direct and selective discrimination with different oxidation potential values of 1.47 and 1.71 V and weak reduction peaks at potential values of -1.37 and -1.48 V, respectively. In addition, electrochemical performance of the modified electrode was investigated in mixed solution of D- and L-MA. The results show that the produced electrode can be used as electrochemical chiral biosensor for MA.
authors.affiliation: Science Institute, Selcuk University, 42003 Selcuklu, Konya, Turkey; Department of Science and Technology, Ahmet Kelesoglu Education Faculty, Necmettin Erbakan University, 42099 Meram, Konya, Turkey.
authors.forename: Erhan
authors.initials: E
authors.lastname: Zor
authors.affiliation: Department of Chemistry Education, Ahmet Kelesoglu Education Faculty, Necmettin Erbakan University, 42099 Meram, Konya, Turkey.
authors.forename: Ahmet O
authors.initials: AO
authors.lastname: Saf
authors.affiliation: Department of Chemistry Education, Ahmet Kelesoglu Education Faculty, Necmettin Erbakan University, 42099 Meram, Konya, Turkey. Electronic address: halukbingol@gmail.com.
authors.forename: Haluk
authors.initials: H
authors.lastname: Bingol
authors.affiliation: Department of Chemistry, Science Faculty, Selcuk University, 42031 Selcuklu, Konya, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ersoz
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry; D055767:Immobilized Proteins / Q000737:chemistry; D008333:Mandelic Acids / Q000737:chemistry* / Q000302:isolation & purification; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D013237:Stereoisomerism; D005719:gamma-Globulins / Q000737:chemistry
chemical_list: D055767:Immobilized Proteins; D008333:Mandelic Acids; D010087:Oxides; D005719:gamma-Globulins; D002244:Carbon; D006108:Graphite; C037938:mandelic acid
keywords: Chiral discrimination; Chiral sensor; Mandelic acid; Reduced graphene oxide; γ-Globulin