Mathematical modeling and experimental results of a sandwic-type amperometric biosensor

MARCELO ROMERO; ANA BARUZZI; FERNANDO GARAY

ELSEVIER SCIENCE SA

Año: 2012 vol. 162 p. 284 - 284

comprehensive numerical treatment of the diffusion and reaction within a sandwich-type amperometric biosensor is presented. The model considers that the enzyme reacts according to a ping-pong mechanism and that it is entrapped into a so-called enzymatic matrix placed between two diffusion membranes. It is found that the concentrations of reagents and products within the sensor are difficult of being compared to those of the bulk. In this regard, the use of approximate analytical solutions would involve errors in the analysis of kinetic parameters corresponding to this kind of biosensors. Provided the mediator species are in high concentration or diffuse much faster than the substrate, the response time of a biosensor of this kind would be determined by the diffusion of the substrate though the external membrane. In this sense, those systems with immobilized mediators, in which diffusion of electrons or holes is assumed for the charge transport process, could