The feasibility of using and the performance of non-biological polyelectrolyte multilayer (PEM) films to facilitate cell attachment on titanium-tungsten alloy/gold (TiW/Au) electrodes for the detection of cellular responses in cell assays are investigated. PEMs are used rather than extracellular matrix (ECM) proteins, which are commonly utilized as cell adhesion promoters on planar electrodes, because the integrity of ECM proteins degrades over time and therefore, decreases the lifetime of biosensors. Poly(ethylene imine) (PEI), sodium poly(styrene sulfonate) (PSS), and poly(allylamine hydrochloride) (PAH) were the polyelectrolytes deposited onto the electrode surface to provide NIH-3T3 mouse fibroblast cells with a biocompatible interface. The deposition was verified with atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). Cellular response on the PEMs-modified surface was assessed by cell viability measurements and cell morphology imaging. The PEMs-modified electrodes were found to show a 15% increase in impedance due to cell proliferation, and to have an 82% efficiency in impedance detection when compared to an unmodified device. This work demonstrated 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.
Citation: Journal of Research (NIST JRES) -
NIST Pub Series: Journal of Research (NIST JRES)
Pub Type: NIST Pubs
biosensors, polyelectrolyte multilayers (PEMs), biocompatible electrodes, cellular impedance, cell confluency detector, cell proliferation monitoring