Sensitive pH detection on gold interdigitated electrodes as an electrochemical sensor

Miniaturized in-house high-performance sensors are mandatory for implementing the current needs efficiently. With the microsystems, electrode material is crucial to overcome the above immediate necessity. In this study, gold interdigitated electrode (AuIDE) was overlaid on the silicon (Si) substrate using conventional photolithography process and tested to be applicable as a chemical sensor between the pH range of 3 and 12. The AuIDE was physically characterized by low and high power microscopic and scanning electron microscopic imaging. Further, 3D nano profiler was used to analyze the development on the surface structure. The designed AuIDE has 4 μm consecutive gaps between 6 μm width IDE finger electrodes. The bare IDE was electrically characterized by I–V curves. This microsensor was also tested with different laboratory and commercially relevant solutions and revealed that the stability is in the pH range between 3 and 12. Comparative analysis of AuIDE sensor with commercially available pH meter revealed that AuIDE sensor has ± 0.1 tolerance. This study has demonstrated that chemical behavior of the electrode through pH calibration for further applications in the field of chemical sensors with amperometric approach.