Biomimetic surface patterning for long-term transmembrane access

Abstract

Here we present a planar patch clamp chip based on biomimetic cell membrane fusion. This architecture uses nanometer length-scale surface patterning to replicate the structure and function of membrane proteins, creating a gigaohm seal between the cell and a planar electrode array. The seal is generated passively during cell spreading, without the application of a vacuum to the cell surface. This interface can enable cell-attached and whole-cell recordings that are stable to 72 hours, and generates no visible damage to the cell. The electrodes can be very small (<5 μm) and closely packed, offering a high density platform for cellular measurement.

Nanovolcano microelectrode arrays: toward long-term on-demand registration of transmembrane action potentials by controlled electroporation

“…After ethanol rinsing, the microelectrode arrays were thoroughly rinsed with sterile deionized water. As previously demonstrated, hexanethiols do not attach to the Pt electrode 26 . For nonpatterned devices, the hexanethiol solution was replaced by pure ethanol.…”

“…The gold layer is exposed along the upper rim of the nanovolcano and is functionalized with alkanethiol self-assembled monolayers 25 . This functionalization has been previously shown in planar electrodes to support the formation of gigaohm seals lasting several days 26 . Further facilitating seal formation, as previously reported for nanopillars 27,28 , the 100-nm-thin upper rim of the nanovolcano induces high-curvature regions in the membrane of contacting cells, which are expected to maximize the coupling between the cell and the electrode.…”

“…Regarding electroporation voltage amplitudes, V EP = 3 V provided an adequate balance between sufficiently reducing the junctional resistance and preventing induction of damage to the seal. As reported in the literature 26 , electroporation damages seal resistances, and the poor recording characteristics reported with V EP = 4 V are a likely example of this circumstance.…”

Ion beam etching redeposition for 3D multimaterial nanostructure manufacturing

“…Specifically, the structure shown in Fig. 2e is very similar to the multimaterial feature built by Van Dersarl and Renaud 14 , where “unconventional” top-down techniques were used to fabricate a 10-nm-thick protruding gold nanoring sandwiched between two Ti layers and one SiO 2 layer surrounding a planar electrode. The purpose was to optimize the cell−electrode interface and improve the electrophysiological recording quality.…”

“…Even sub-10-nm nanostructures composed of several materials were fabricated using ingenuities. Chemical-mechanical polishing performed on tapered microstructures covered with a stack of several materials led to 5-nm-thick concentric Ti-Au-Ti nanorings at the wafer scale 14 . Similar examples can be found in the literature; however, none describe a reliable method to produce complex 3D multimaterial nanostructures at the wafer scale.…”