This work demonstrates the successful modification of screen-printed electrodes using functionalized titanate nanowires for producing a peroxide biosensor. Titanate nanowires were synthesized by the hydrothermal method and characterized using physico-chemical techniques. The surface of the nanowires was modified with (3-aminopropyl)trimethoxysilane and glutaraldehyde to immobilize horseradish peroxidase through covalent bound, obtaining a surface coverage of 1.62mg of enzyme/m2. The surface of screen-printed carbon electrodes was modified with peroxidase-containing nanowires. Cyclic voltammetry and chronoamperometry were employed to study the electrochemical properties of the nanostructured electrode. A low hydrogen peroxide reduction potential around -0.98V (vs Ag, pH7.0) was observed, with linear response in the range of 40 to 560μmolL-1, detection limit of 10.7μmolL-1 and good stability. Reproducibility relative standard deviation was as low as 4.7%. For repeatability, deviation was 3.3%.
Keywords: Biosensor; Enzyme immobilization; Horseradish peroxidase; Hydrogen peroxide; Screen-printed electrode; Titanate nanowires.
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