In this paper, an electrical signal detection system for microbiochips is proposed to overcome the limitations of conventional optical systems such as bulky system size and high manufacturing cost. An electrical detection system with interdigitated microelectrodes is fabricated using MEMS technology. High conductive nano size gold particles were selected for the system to detect biological reactions between bio materials in the microbiochip. Experiments were performed with variations of particle densities and electrode gaps. In addition, a simulation to predict the electrical resistance of the microbiochip was developed. Both the simulation and experimental data show that the conductivity increases as the gap becomes narrower and the particle density higher.