Enzyme-electropolymer-based amperometric biosensors: An innovative platform for time-temperature integrators

Abstract

A novel exogenous time - temperature integrator (TTI) based on an amperometric glucose oxidase biosensor is presented. The TTI consists of the enzyme entrapped within an electrochemically generated poly(o-phenylenediamine) (PoPD) thin film deposited on the interior wall of a platinum (Pt) or a platinized stainless steel (Pt-SS) capsule. After thermal treatment, the TTI is mounted in a continuous flow system and connected to a potentiostat for amperometric detection of residual enzyme activity. A measurement is completed within 10 min. Isothermal treatments were carried out between 70 and 79.7°C. Thermal inactivation of the immobilized enzyme followed apparent first-order kinetics with z values of 6.2 ± 0.6 and 6.6 ± 0.8°C for Pt and Pt-SS capsules, respectively. These z values suggest that the proposed TTIs have the potential to assess pasteurization processes that target microorganism such as Listeria monocytogenes and Escherichia coli O157:H7. © 2005 American Chemical Society.