Tyrosinase biosensor based on multiwall carbon nanotubes - titanium oxide nanocomposite for catechol determination

摘要

Multiwall carbon nanotubes-titanium oxide nanocomposite (MWCNTs-TiO2) was formed and used as a conductive material for modification of graphite electrode and tyrosinase immobilization. This nanocomposite showed good conductivity, and biocompatibility with the enzyme. Under optimum conditions, the current response was linear to catechol concentration from 0.2 to 2.7 mM with a sensitivity of 85.79 mA/M and a low detection limit of 0.014 mu M, the proposed electrode shows good reproducibility and long-term stability till 25 d. The prepared biosensor was successfully used to measure the catechol in different water samples, with excellent results compared with the spectrophotometric method, at 95% confidence level.