Samal Munidasa

Dept. Of Electrical Engineering & Computer Science



Samal Munidasa is a 4th year biophysics student at the Faculty of Science at York University. Having specialized in bioengineering, Samal is spending the summer exploring the use of electrical impedance spectroscopy (EIS) to characterize cell tissue with Professor Ebrahim Ghafar-Zadeh. Specifically, Samal will be automating a biocompatible microelectrode EIS platform to be used as a non-invasive alternative to current bioelectric recording devices. This platform will offer multiple channels for high throughput screening as well as a user-friendly interface. By the end of the summer, Samal is hoping to have completed a prototype for the device and a thorough analysis of the impedance spectra for neuronal cell tissues. This system is important because it can be applied to various medical applications such as tissue engineering, drug screening, and monitoring biomass. Due to its low-cost and flexibility it can be made available to everyone in either a clinical or research setting.


Automation of an electrochemical impedance spectroscopy (EIS) platform for the characterization of N2a neuroblastoma cell growth

The purpose of the project was to automate and implement an electrochemical impedance spectroscopy (EIS) platform used to characterize the growth of N2a neuroblastoma cells. Neuroblastoma is the cancer of primitive nerve tissue and is common amongst newborns. EIS can be used as a non-invasive diagnostic tool to detect minute changes in the morphology of the neuroblastoma cells during their development. The EIS device consisted of a disposable microchip containing an array of ITO microelectrodes underneath a set of PDMS chambers where the N2A cells were cultured. To automate the current platform, a printed circuit board (PCB), designed with Eagle, was fabricated to control which electrode would perform an impedance measurement, allowing for multiple neuronal samples to be tested in quick succession. The PCB was operated by an Arduino which in turn was controlled in real time by a webpage hosted locally by the runtime environment, node js. The final product was enclosed in a 3D-printed cased designed using AutoCAD. The PCB was integrated with the Metrohm Autolab potentiostat, an electrochemical instrument used to perform EIS measurements over a wide range of frequencies. The Metrohm software was used to develop an equivalent circuit model of the N2a cells based on their impedance spectra. As multiple EIS measurements were taken of the neuroblastoma cells over time, new circuit elements were added to the equivalent model. These elements corresponded to the addition of cell-adhesion molecules and neurites that formed at different stages of neuronal network development. Thus, the EIS system could be used as a diagnostic tool to detect early changes in neuronal tissue composition and can be extended further to identify possible signs of neurological conditions.