Extended Large Area Si/ZnO Heterojunction Biosensor for Assessing Functional Behaviour of Primary Cortical Neuronal Cells

In this study, we report the poly-L-lysine (PLL) coated extended large area p-Si/n-ZnO heterojunction based biosensing device to analyze the influence of functional behavior of primary cortical neuronal cells. Wherein, the proliferation of rat embryonic neurons and neural stem cells is highly influenced by the physicochemical and structural properties of the underlying substrate mimicking the extracellular microenvironment. We observed a significant increase in the impedance values while adhesion of the neuronal cells on the substrate; however, it further got significantly decreased with the progression of various cellular functions neurite outgrowth and network formation. Such neuronal processes might have increased the propagation of flow of current by reducing the resistivity of the PLL treated n-ZnO thin film sensing area. Additionally, through the Nyquist plot, we observed a noticeable decrease in the magnitude of impedance values of the fabricated device. Hence, we believe that the fabricated PLL coated extended large area p-Si/n-ZnO heterojunction biosensor can serve as a favourable device to monitor the influence of functional behavior of neuronal cells.