How low does the oxygen concentration go within a sandwich-type amperometric biosensor?

M. ROMERO; A. M. BARUZZI; F. GARAY

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2012 vol. 174 p. 279 - 279

0925-4005

oftware for the automatic non-linear least squares fit of chronoamperometric responses corresponding to sandwich-type amperometric biosensors has been developed. The so-called Simplex algorithm computes a minimum value for the difference between experimental and theoretical data. The latter consider a numerical model based on a ping-pong reaction mechanism corresponding to an oxidase enzyme that has been immobilized between diffusion membranes. The results obtained from the simulation of a first-generation lactate biosensor in presence of 0.1 mM substrate indicate that the concentration of O2 would decrease only 0.1% with regards to its bulk value. Besides, the concentration of this natural mediator would remain practically unchanged during a typical calibration curve. This is because the rather high diffusion coefficient of O2 and its regeneration at the electrode surface minimize the concentration changes of this species. In addition, it was found that the thicknesses of polycarbo