Three-dimensional fuzzy graphene ultra-microelectrodes for subcellular electrical recordings
microelectrode array, ultra-microelectrodes, electrical recordings, biocompatible, hybrid-nanomaterial, 3D graphene, cardiomyocytes
Microelectrode arrays (MEAs) have enabled investigation of cellular networks at sub-millisecond temporal resolution. However, current MEAs are limited by the large electrode footprint since reducing the electrode’s geometric area to sub-cellular dimensions leads to a significant increase in impedance thus affecting its recording capabilities. We report a breakthrough ultra-microelectrodes platform by leveraging the outstanding surface-to-volume ratio of nanowire-templated out-of-plane synthesized three-dimensional fuzzy graphene (NT-3DFG). The enormous surface area of NT-3DFG leads to 140-fold reduction in electrode impedance compared to bare Au microelectrodes, thus enabling scaling down the geometric size by 625-fold to ca. 2 µm × 2 µm. The out-of-plane morphology of NT-3DFG leads to a tight seal with the cell membrane thus enabling recording of electrical signals with high signal-to-noise ratio (SNR) of > 6. This work highlights the possibility to push the limits of the conventional MEA technology to enable electrophysiological investigation at sub-cellular level without the need of any surface coatings. This presented approach would greatly impact our basic understanding of signal transduction within a single cell as well as complex cellular assemblies.
Tsinghua University Press
Sahil K. Rastogi,Jacqueline Bliley,Laura Matino,Raghav Garg,Francesca Santoro,Adam W. Feinberg,Tzahi Cohen-Karni, Three-dimensional fuzzy graphene ultra-microelectrodes for subcellular electrical recordings. NanoRes.2020, 13(5): 1444–1452