The voltammetric performance of interdigitated electrodes with different electron-transfer rate constants

To explore ways to improve the performance of affinity-based biosensors, we simulated, with 2D and 3D finite element analyses, the cyclic voltammetric (CV) curves for interdigitated electrodes (IDEs) at various electron-transfer rate constants (i.e., the k0 value). The CV curves and the relationships between the limiting current and k0 were obtained and examined. From the 2D models, it is found that the limiting current of IDEs is very sensitive to the change of k0, especially at larger k0 values. As the electrode width (w) decreases, significant enhancements in the sensitivity and lower-detection-limit can be achieved due to the enhanced mass transport near the IDEs. From the 3D models, it is found the limiting current can be further improved by using 3D nanorod-modified IDEs. This study presents some important information for improving the design and development of future electrochemical-based biosensors.