Transport and kinetic analysis of amperometric response towards PPO-based rotating disk bioelectrodes

[Display omitted] •Transport and kinetics of PPO-based rotating disc electrodes for CEC mechanism are discussed.•The coupled system of strongly nonlinear reaction–diffusion equations was solved using HPM.•The analytical representation of concentration and current is determined for transient conditions.•The closed-form expression of sensitivity and amplification factor are obtained. This work aims to discuss a theoretical model that would account for the kinetics and transport of substrates and product in rotating disc bioelectrodes based on the PPO system. The nonlinear term associated with the CEC's mechanism is a part of the nonlinear reaction–diffusion system upon which this model is based. The homotopy perturbation approach has been used for the first time to solve thecoupled system of strongly nonlinear reaction–diffusion equations of PPO-based rotating disc electrodes for the CEC mechanism under non-steady-state conditions. For all potential values of the diffusion and kinetic parameters, the approximate analytical expression of concentrations of phenol, catechol, and o-quinone and the current response are presented. Additionally, the bioelectrode's phenol substrate sensitivity and amplification factor were shown in terms of rotational speed and enzyme layer thickness. This problem's numerical solution is also presented using the Scilab/Matlab software. Moreover, a satisfactory agreement is noted when the analytical and numerical results are compared for experimental values of the parameter.