Selective Impedimetric Interdigitated Electrode for Sensing Gaseous, Biological, and Inorganic Targets: A State-of-the-Art Review

Sensor systems that comprise interdigitated electrode (IDE) transducer(s) and selectivity layer(s) are an appropriate platform for versatile sensor applications. Such systems have generally used non-faradic, label-free impedance spectroscopic methods for harnessing the signal from the IDEs. While there is an increasing need for sensors (or sensor systems) to be sensitive, smaller, easier to operate, and cost-effective, the development and use of IDE-based sensors in multiple application domains make it very challenging. Thus, a state-of-the-art review of interdigitated electrode-based sensors is justified and is the primary focus of this paper. This paper reviews the working principles, mathematical models, design architectures, and fabrication methods of IDE-based sensors in three specific application domains (gaseous, biological, and inorganic). The performance of the IDE-based sensors across different applications, along with their limitation, have been illustrated. The emerging trend of 3-D interdigitated electrodes as sensing platforms has been discussed with additional perspectives on their overall future research needs.