title: Amperometric determination of H2O2 at nano-TiO2/DNA/thionin nanocomposite modified electrode.
abstract: We report electrochemical preparation and characterization of a new biosensor made of nanostructured titanium dioxide (nano-TiO2) particles and deoxyribonucleic acid (DNA). Thionin (TN) redox mediator was electrochemically deposited onto DNA/nano-TiO2 modified glassy carbon electrode (GCE). The X-ray diffraction analysis, atomic force microscope (AFM) and scanning electron microscope (SEM) were used for surface analysis of TN/DNA/nano-TiO2 film. In neutral buffer solution, TN/DNA/nano-TiO2/GCE biosensor exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) and oxygen (O2). The biosensor shows excellent analytical performance for amperometric determination of H2O2, at reduced overpotential (-0.2V). The detection limit and liner calibration range were found to be 0.05 mM (S/N=3) and 0.05-22.3 mM, respectively. In addition, determination of H2O2 in real samples was carried out using the new biosensor with satisfactory results. The TN/DNA/nano-TiO2/GCE showed stable and reproducible analytical performance towards the reduction of H2O2. This biosensor can be used as an amperometric biosensor for the determination of H2O2 in real samples.
authors: Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1 Section 3 Chung-Hsiao East Road, Taipei, Taiwan, ROC.
authors: Po-Hsun
authors: PH
authors: Lo
authors: S Ashok
authors: SA
authors: Kumar
authors: Shen-Ming
authors: SM
authors: Chen
mesh_terms: D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties; D054809:Thionins / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D054809:Thionins; C009495:titanium dioxide; D002244:Carbon; D004247:DNA; D006861:Hydrogen Peroxide; D014025:Titanium; D010100:Oxygen