title: Modification of glassy carbon electrode with a polymer/mediator composite and its application for the electrochemical detection of iodate.
abstract: A modified glassy carbon electrode was prepared by depositing a composite of polymer and mediator on a glassy carbon electrode (GCE). The mediator, flavin adenine dinucleotide (FAD) and the polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) were electrochemically deposited as a composite on the GCE by applying cyclic voltammetry (CV). This modified electrode is hereafter designated as GCE/PEDOT/FAD. FAD was found to significantly enhance the growth of PEDOT. Electrochemical quartz crystal microbalance (EQCM) analysis was performed to study the mass changes in the electrode during the electrodeposition of PEDOT, with and without the addition of FAD. The optimal cycle number for preparing the modified electrode was determined to be 9, and the corresponding surface coverage of FAD (Γ(FAD)) was ca. 5.11×10(-10)mol cm(-2). The amperometric detection of iodate was performed in a 100 mM buffer solution (pH 1.5). The GCE/PEDOT/FAD showed a sensitivity of 0.78 μA μM(-1) cm(-2), a linear range of 4-140 μM, and a limit of detection of 0.16 μM for iodate. The interference effects of 250-fold Na(+), Mg(2+), Ca(2+), Zn(2+), Fe(2+), Cl(-), NO(3)(-), I(-), SO(4)(2-) and SO(3)(2-), with reference to the concentration of iodate were negligible. The long-term stability of GCE/PEDOT/FAD was also investigated. The GCE/PEDOT/FAD electrode retained 82% of its initial amperometric response to iodate after 7 days. The GCE/PEDOT/FAD was also applied to determine iodate in a commercial salt.
authors: Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors: Ta-Jen
authors: TJ
authors: Li
authors: Chia-Yu
authors: CY
authors: Lin
authors: A
authors: A
authors: Balamurugan
authors: Chung-Wei
authors: CW
authors: Kung
authors: Jen-Yuan
authors: JY
authors: Wang
authors: Chih-Wei
authors: CW
authors: Hu
authors: Chun-Chieh
authors: CC
authors: Wang
authors: Po-Yen
authors: PY
authors: Chen
authors: R
authors: R
authors: Vittal
authors: Kuo-Chuan
authors: KC
authors: Ho
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry; D005898:Glass / Q000737:chemistry; D007452:Iodates / Q000032:analysis*; D011108:Polymers / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods; D013499:Surface Properties
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D007452:Iodates; D011108:Polymers; C121383:poly(3,4-ethylene dioxythiophene); D005182:Flavin-Adenine Dinucleotide; D002244:Carbon