Model of a conductimetric urea sensor

A model for predicting the response of a conductimetric urea sensor was developed. The sensor under consideration is formed by immobilizing the enzyme urease onto the surface of a planar interdigitated electrode array. The analysis combines a mass transport model with an electromagnetic fields model for calculating interelectrode impedance. The transport model was used to determine the evolution of charged reaction products in time and space. Interelectrode impedance was calculated from the resulting ionic conductivity profiles using the fields model. The calibration curve resulting from the model predictions was in good agreement with experimental data, using a single adjustable parameter