Abstract:
There is growing need for new biosensing technologies that are more rapid and convenient to use for onsite sensing. Impedance based electrochemical sensor is a promising candidate due to simplicity in its sensing mechanism. However, like other emerging biosensors, specificity, sensitivity, and reliability are major obstacles that limit their use in real-life applications. Electrode geometry and 3D shape design optimization have been popular research directions for improved sensor performance. This study aimed to develop a modelling process, using finite element modelling, that allows calculation of electrode impedance for different electrode geometries and shapes. In addition, a method for comparing sensor sensitivity was presented using bacterial targets as case study. In this article, a numerical model was developed for electrodes in standard test medium. Impedance simulations were performed for different electrode shapes, namely flat, ridge, and trough. Moreover, the effects of target binding on solution conductivity and diffusion were simulated. It was found ridge shaped electrodes showed the greatest change in diffusion impedance upon target recognition. However, different shapes gave maximum change in solution impedance depending on the position of bound target.