Substrate-Tight Graphene Transmembrane-nanofluidic Devices

Abstract

Nanopores in 2D membranes like graphene have great potential for applications such as single-molecule sensing, ion sieving, and harvesting osmotic power. A critical challenge, however, has been to ensure the stability of these nanofluidic transmembrane devices, as the ultrathin graphene membranes tend to delaminate and peel away from their substrates when exposed to aqueous solutions. In this study, it is shown that using a pyrene-based coating prevents delamination and allows graphene to remain freestanding over a SiN aperture for several days in an electrolyte. The pyrene molecules interact strongly with the graphene through π-π bonding, adhering the graphene to the substrate. Additionally, the pyrene-based adhesion layer remarkably increases the success rates of the graphene transmembrane devices from 4% to 76.2%. The results underscore the importance of using adhesion layers to enhance the stability of graphene in nanofluidic devices and prolong their operational lifespan. It enables the development of more robust graphene-based nanofluidic devices for a wide range of applications necessitating free-standing graphene.

Keywords: (sub)nanofluidics; adhesion; graphene; ion transport; pyrene.