Transport and kinetics in an electroenzymatic process incurred in PPO-based rotating disk bioelectrodes

Abstract

• A nonlinear system of equation arising in PPO-based rotating disc electrodes is studied. • The reliable and closed-form of expression of concentrations and current are obtained. • The effect of rotation rate on sensitivity and amplification factors is discussed. • Numerical and analytical results are compared for experimental values of parameters. The motivation for this work was to develop a theoretical analysis corresponding to the transport and kinetics of substrate and product in PPO-based rotating disk bioelectrodes. This model is based on a nonlinear reaction–diffusion system containing the nonlinear term related to the CEC' mechanism. The hyperbolic function approach was used to solve the nonlinear coupled system of reaction–diffusion equations. The approximate analytical expressions concentrations of phenol, catechol and o-quinone and current response for all possible diffusion and kinetic parameters values are reported. The bioelectrode's sensitivity and amplification factor towards phenol substrate were also presented in terms of rotation rate and enzyme layer thickness. The numerical solution of this problem is also reported using Scilab/Matlab program. Also, a satisfactory agreement is noted between the analytical and numerical results upon comparison.