Bioelectronic Sensor for Cellular Assays Using Polyelectrolyte Multilayer-Modified Electrodes

Cell-based impedance biosensors provide non-invasive, quantitative, and instantaneous detection of cellular responses to applied stimuli. Extracellular matrix proteins, which degrade over time, are commonly used as cell adhesion promoters on planar electrodes, but decrease the lifetime of biosensors. In this work, the feasibility of using non-biological polyelectrolyte multilayers (PEMs) to facilitate cell attachment on titanium-tungsten alloy/gold electrodes for cell assays is investigated. The PEMs-modified electrode system is modeled as an equivalent electrical circuit and the addition of cells to the system is defined by their electrical properties. Electrode performance is characterized by cyclic voltammetry and impedance spectroscopy. The electrodes are found to have the ability to specifically probe non-faradaic processes and show a 15% increase in impedance due to cell proliferation. This thesis work demonstrates the use of PEMs-modified electrodes for the continuous monitoring of cell proliferation and for the future application of probing cell confluency in microfluidic cytotoxicity assays