Modeling macroscopic transport of superoxide radicals through nonoheterogeneous biosensor film

We develop a mathematical model to represent the transport phenomena and electrochemical reaction kinetics during amperometric measurement of superoxide radical concentration using ZnO-polymer nanocomposite sensor. This model assumes a logarithmic normal distribution for the nanoparticles immobilized in the polymer matrix and an empirical relation for the diffusion coefficient of superoxide radicals as a function of pore volume fraction. A kinetic with secondary order rate constant is used to represent the electrochemical reactions of electron transfer from the superoxide radicals to nanoparticles. The predicted results include the effect of diffusion coefficient on concentration and electrical conductivity.