Amperometric determination of H2O2 at nano-TiO2/DNA/thionin nanocomposite modified electrode

作者：Lo Po Hsun; Kumar S Ashok; Chen Shen Ming^*

来源：Colloids and Surfaces B: Biointerfaces , 2008, 66(2): 266-273.

DOI：10.1016/j.colsurfb.2008.07.003

• DNA modified electrode
• hydrogen peroxide detection
• nanostructured TiO2
• electrocatalysis
• biosensors

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 Xray 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 (O-2). The biosensor shows excellent analytical performance for amperometric determination of H2O2, at reduced overpotential (-0.2 V). 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.

• 出版日期2008-10-15