Interdigitated Electrode are known as one of the hallmark of biosensors because of its numerous applications. Biosensors projects to be preferable devices especially in hospitals and other medical faculties as well as in other interdisciplinary fields because of its small size and high sensitivity. Since size plays a salient role in sensitivity and selectivity, in this research, 140 nm IDEs and 50μm IDEs were used to test the electrical characterization using current-voltage (I-V) for comparison. The morphological of IDEs were taken by using High Power Microscope with 50x magnification and Scanning Electron Microscope (SEM). Aim of this research is to test electrical characterization on bare aluminium IDEs and IDEs doped with pH solution for both nano Interdigitated Electrode (nIDEs) and also micro Interdigitated Electrodes (μIDEs). Each IDE was tested to achieve a stable pattern of electrical measurements and results were obtained by current-voltage graph. The pH solutions used for this research from pH 2 to pH 12 were dropped on nano IDEs as well as micro IDEs and conductivity was tested using two-point probe and based on the results it was proven that the conductivity of both types of IDEs differs depending on their finger gap size.