Effect of the Wire Diameter on the Stability of Micro-Scale Ag/AgCl Reference Electrode

Silver chloride that is commonly used as a reference electrode in many chemical sensors is stable when its dimensions are relatively large. However, its use in sensors, especially in nanosensors, requires that its size be reduced significantly. In this paper, we report that the stability of very small silver chloride electrodes could be obtained if a specific potential is applied. The AgCl wires produced by electrodeposition are investigated by the chronoamperometry technique. Scanning electron microscopy (SEM) is used to study the properties of the surface of the fabricated wires surface obtained. We found that the stability depends on the silver chloride surface morphology. Indeed, the Ag/AgCl wire provided a more stable potential when its surface morphology is like nanosheets. It seems that this surface morphology obtained for Ag/AgCl wire with a micrometric diameter is a promising element that could be used to measure a variety of biological parameters such as membrane potential, intracellular free ion concentrations and cell-to-cell communication.