Tau is a neuronal protein responsible for microtubule formation [1]. It is also the pathological protein active in the Alzheimer’s Disease (AD) pathway. When Tau begins to aggregate as a result of misfolding, the neuronal cells die due to the lack of microtubule formation and can take on prion-like properties [2]. Therefore, detection of aggregated Tau can serve as a powerful tool in the early diagnosis of AD and dementia related diseases. As has been previously demonstrated, Tau 441 can be detected with an electrochemical immunoassay based on the electrochemical impedance spectroscopy (EIS) by using gold electrode [3]. The EIS was also used to monitor interactions between Tau protein and Heparin [4]. Herein, we describe use of EIS to monitor and detect Tau and its aggregates by using gold electrode modified to include a biotinylated aptamer to tau and streptavidin-Au sensor through a series of surface modifications. Surface modifications were characterized using EIS and CV. After modifying the surface of the electrode, the detection of Tau was achieved using EIS. Aggregation of tau was also monitored as a function of Tau or Heparin concentrations, and incubation time and temperature. The control experiments included, Tau-free surface, Heparin-free solution, buffer solution in order to minimize aggregation. The charge transfer resistance, Rct, was determined by fitting the experimental data to the equivalent circuit. The Rct values for Tau-films on gold surface were compared prior and post aggregation. The Rct values were highly dependent on the experimental conditions. Data indicate that this electrochemical sensor holds great promise for detection of neurodegenerative biomarkers which undergo aggregation.