Computational Modelling of Wire Biosensor with Competitive Substrates Conversion

Glucose biosensors are analytical devices used mainly for the recognition of glucose in blood. A wire biosensor utilizing a competitive substrates conversion is analysed in this paper. Two substrates (oxygen and glucose) are competing over the single enzyme (Aspergillus niger glucose oxidase) in the analysed reactions. However, oxygen concentration is not of any importance in this case and it is considered as disturbance. The purpose of this work was to define the parameter values of the biosensor, at which oxygen concentration does not affect the response of the biosensor. The behaviour of the biosensor is defined by the mathematical model with reaction-diffusion equations of non-linear type. The suggested mathematical model is solved numerically, by using finite difference technique, as the analytical solutions exist only for a very few selected cases because of the non-linearity in the reaction term. The simulations showed complex biosensor dynamics at various values of enzymatic membrane thickness and concentration. The calibration curves signifying the effective range of the biosensor operation were provided.