Modelling Amperometric Biosensors Based on Chemically Modified Electrodes

Area of Science:

• Electrochemistry
• Biochemical Engineering
• Mathematical Modeling

Background:

• Amperometric biosensors rely on chemically modified electrodes for analyte detection.
• Accurate modeling is essential for optimizing biosensor performance and understanding response mechanisms.

Purpose of the Study:

• To numerically model the response of an amperometric biosensor.
• To investigate the influence of key parameters on biosensor kinetics and output.

Main Methods:

• Developed a mathematical model based on non-linear reaction-diffusion equations for a two-compartment biosensor (enzyme and diffusion layers).
• Derived a dimensionless model to identify governing parameters.
• Employed the finite difference technique for digital simulation.
• Validated the model using analytical solutions for specific cases.

Main Results:

• Numerical analysis of transition and steady-state conditions was performed by varying model parameters.
• Investigated the impact of substrate concentration, mediator concentration, and layer thicknesses on biosensor response.
• Calculations demonstrated complex biosensor kinetics, particularly under mixed diffusion and enzyme-substrate interaction limitations.

Conclusions:

• The developed mathematical model provides insights into amperometric biosensor behavior.
• Understanding complex kinetics is vital for optimizing biosensor design and application.
• Parameter variations significantly affect biosensor output, highlighting the need for careful calibration.