Graphene and nanowire transistors for cellular interfaces and electrical recording

Nanowire field effect transistors (NW FHTs) have been shown in be powerful building blocks for nanoscale bioelectronic interfaces with cells and tissue due to their excellent sensitivity and their capability to form strongly coupled interfaces with cell membranes. Graphene has also been shown to be an attractive building; block for nanoseale electronic devices although little is known about its interfaces with cells and tissue. Here we report the first studies of graphene field effect transisrors (Gra-FETs) as well as combined Gia- and NW-FETs interfaced to electrogenic cells. Gra-FET conductance signals recorded from spontaneously bearing embryonic chicken cardiomyocytes yield well-defined extracellular signals wirh signal-to-noise ratio rourinely >4. The conductance signal amplitude was tuned by varying the Gra-FET working region through changes in water gate potential, V_wg, Signals recorded from cardiomyocyres for different V_wg result in constant calibrated exrracellular voltage, indicating a robust graphene/cell interface. Significantly, variations in V_wg across the Dirac point demonstrate the expected signal polarity flip, thus allowing, for the first time, both n and p type recording to be achieved from the same Gra-FET simply by offsetting V_wg. In addition, comparisons of peak to peak recorded signal widths made as a function of Gra-FET device sizes and versus NW- FET allowed an assessment of relative resolution in extracellular recording. Specifically, peak-to-peak widths increased with the area of Gra-FET devices, indicating an averaged signal from different points across the outer membrane of the beating cells. One-dimensional silicon NW- FETs incorporated side by side with the two-dimensional Gra-FET devices further highlighted limits in both temporal resolution and multiplexed measurements from the same cell for the different types of devices. The distinct and complementary capabilities of Gra- and NW-FETs could open up unique opportunities in the field of bioelectronics in the future.