title: A novel H2O2 sensor based on the enzymatically induced deposition of polyaniline at a horseradish peroxide/aligned single-wall carbon nanotubes modified Au electrode.
abstract: A novel H(2)O(2) sensor based on enzymatically induced deposition of electroactive polyaniline (PANI) at a horseradish peroxide (HRP)/aligned single-wall carbon nanotubes (SWCNTs) modified Au electrode is fabricated, and its electrochemical behaviors are investigated. Electrochemical impedance spectroscopy of the sensor confirmed the formation of PANI on SWCNTs through the HRP catalytic reaction. Cyclic voltammograms of PANI/HRP/SWCNTs modified Au electrodes showed a pair of well-defined redox peaks of PANI with reduction peak potentials of 0.211 and oxidation peak potentials of 0.293 V in 0.1 M HOAc-NaOAc (pH 4.3) solution. The oxidation peak current response of PANI is linearly related to H(2)O(2) concentration from 2.5 μM to 50.0 μM with a correlation coefficient of 0.9923 and a sensitivity of 200 μA mM(-1). The detection limit is determined to be 0.9 μM with a signal-to-noise ratio of 3. Thus, the synergistic performance of the enzyme, the highly efficient polymerization of PANI, and the templated deposition of SWCNTs provided an extensive platform for the design of novel electrochemical biosensors.
authors.affiliation: Institute of Analytical Science/Shaanxi Province Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an, China.
authors.forename: Na
authors.initials: N
authors.lastname: Tang
authors.forename: Jianbin
authors.initials: J
authors.lastname: Zheng
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Sheng
authors.forename: Hongfang
authors.initials: H
authors.lastname: Zhang
authors.forename: Ruixiao
authors.initials: R
authors.lastname: Liu
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D055162:Biocatalysis; D015374:Biosensing Techniques / Q000379:methods*; D002264:Carboxylic Acids / Q000737:chemistry; D058266:Dielectric Spectroscopy; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D037742:Nanotubes, Carbon / Q000737:chemistry*; D058105:Polymerization; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D000814:Aniline Compounds; D002264:Carboxylic Acids; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; C416807:polyaniline; D006046:Gold; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase