Growing TiO2 nanotubes on graphene nanoplatelets and applying the nanonanocomposite as scaffold of electrochemical tyrosinase biosensor

In this work, TiO2 nanoparticles were grown into TiO2 nanotubes (TNTs) on graphene nanoplatelets (GNPs) surface to produce a GNP-TNT nanocomposite via an alkaline hydrothermal method. The nanocomposite was then characterized by transmission electron microscopy, scan electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and AC impedance spectroscopy. The electrochemical performance of GNP-TNT nanocomposite and TNTs modified tyrosinase (Tyr) biosensors was studied using voltammetric technique. Finally, the as-prepared biosensors were applied for the determination of catechol by chronoamperometry. Two linear ranges (0.30-110 mu M) and (110.5-390 mu M), and a detection limit of 0.055 mu M were obtained by GNP-TNT nanocomposite modified biosensor. Furthermore, the tyrosinase biosensor exhibited satisfactory precision, stability and recovery. (C) 2014 Elsevier B.V. All rights reserved.