  A wide range of approaches have been explored to meet the challenges of
graphene nanostructure fabrication, all requiring complex and high-end
nanofabrication platform and suffering from surface contaminations, potentially
giving electrical noise and increasing the thickness of the atomically thin
graphene membrane. Here, with the use of an electrical pulse on a low
capacitance graphene-on-glass (GOG) membrane, we fabricated clean graphene
nanopores on commercially available glass substrates with exceptionally low
electrical noise. In situ liquid AFM studies and electrochemical measurements
revealed that both graphene nanopore nucleation and growth stem from the
electrochemical attack on carbon atoms at defect sites, ensuring the creation
of a graphene nanopore. Strikingly, compared to conventional TEM drilled
graphene nanopores on SiN supporting membranes, GOG nanopores featured an
order-of-magnitude reduced broadband noise, which we ascribed to the
electrochemical refreshing of graphene nanopore on mechanically stable glass
chips with negligible parasitic capacitance (1 pF). Further experiments on
double-stranded DNA translocations demonstrated a greatly reduced current
noise, and also confirmed the activation of single nanopores. Therefore, the
exceptionally low noise and ease of fabrication will facilitate the
understanding of the fundamental property and the application of such
atomically thin nanopore sensors.
