IDE-based Electrochemical Sensors

Silicon chip-based interdigitated electrode (IDE) electrochemical sensors represent a state-of-the-art approach to localised pH control and precise electrochemical analysis. These sensors utilise two comb-like interdigitated electrode arrays: one generates hydroxide (OH⁻) or hydrogen (H⁺) ions to adjust pH levels, while the other, modified comb is dedicated to analyte detection. The nanosensor electrodes are meticulously fabricated on a silicon chip using advanced electron beam lithography and lift-off techniques. Additional on-chip counter and quasi-reference electrodes are integrated through optical lithography and safeguarded with a silicon nitride passivation layer, effectively preventing undesired electrochemical reactions during measurements. This design ensures exceptional precision and reliability for various electrochemical sensing applications.

To enhance detection capabilities, the sensor material is tailored and analysed using various electrochemical characterisation techniques, including cyclic voltammetry and square wave voltammetry. These methodologies allow for the precise detection of specific heavy metals and nutrients.

Field testing at Technology Readiness Level (TRL) 5 provided critical insights into the sensor system’s performance and durability under real-world conditions. As the system advances towards TRL 7–8, significant adjustments have been made to optimise stability and accuracy across diverse environmental factors such as temperature, moisture, and soil composition. Additionally, efforts have focused on improving power consumption and data communication to ensure the system’s capability for long-term field operations.