title: Amperometric hydrogen peroxide biosensor based on immobilization of DNA-Cu(II) in DNA/chitosan polyion complex membrane.
abstract: DNA/chitosan polyion complex membrane was used as a support for immobilization of electrocatalytic species-copper ions, which specifically bound to dsDNA and catalyzed the hydrogen peroxide reduction. The polyion complex membrane consisted with DNA-Cu(II) complex and chitosan was prepared on a glassy carbon electrode (GCE). Electrochemical measurements of the DNA-Cu(II)/chitosan membrane-modified GCE revealed that the copper ion embedded in the DNA/chitosan layer exhibited good electrochemical behaviors. The DNA-Cu(II)/chitosan/GC electrode showed an excellent electrocatalytic activity for the H2O2 reduction. Even in the presence of dissolved oxygen, the sensor exhibited highly sensitive and rapid (response time, about 6 s) response to H2O2. The steady-state cathodic current responses of the sensor obtained at -0.2 V versus Ag/AgCl in air-saturated 100 mmol/L phosphate buffer (pH 5.0) increased linearly up to 10 mmol/L with the detection limit of 3 μmol/L. Effects of applied potential and buffer pH upon the response currents of the sensor were investigated for an optimum analytical performance. Ascorbic acid and glucose almost have no interference to measurement of H2O2. In addition, the sensor exhibited good reproducibility.
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China. gtt@ustl.edu.cn
authors.forename: Tingting
authors.initials: T
authors.lastname: Gu
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Life Science & Green Chemistry, Saitama Institute of Technology, Fukaya 369-0293, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hasebe
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D048271:Chitosan / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004560:Electricity; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005898:Glass; D006861:Hydrogen Peroxide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D013997:Time Factors
chemical_list: D007477:Ions; D008567:Membranes, Artificial; D003300:Copper; D004247:DNA; D048271:Chitosan; D006861:Hydrogen Peroxide