Facile and ultraclean graphene-on-glass nanopores by controlled electrochemical etching

Abstract

Awiderangeof approacheshavebeenexploredtomeet thechallengesof graphenenanostructure fabrication, all requiringcomplexandhigh-endnanofabricationplatformandsuffering fromsurfacecontaminations, potentiallygivingelectrical noiseandincreasingthethicknessof theatomicallythingraphenemembrane.Here,withtheuseof anelectricalpulseona low capacitance graphene-on-glass (GOG)membrane, we fabricated clean graphene nanopores on commercially available glass substrateswithexceptionallylowelectricalnoise. InsituliquidAFMstudiesandelectrochemicalmeasurementsrevealedthatboth graphenenanoporenucleationandgrowthstemfromtheelectrochemical attackoncarbonatoms at defect sites, ensuring the creationof a graphene nanopore. Strikingly, compared to conventional TEMdrilled graphene nanopores onSiNsupporting membranes,GOGnanopores featuredanorder-of-magnitudereducedbroadbandnoise,whichweascribedtotheelectrochemical refreshing of graphene nanopore onmechanically stable glass chips with negligible parasitic capacitance (∼1 pF). Further experiments on double-strandedDNA translocations demonstrated a greatly reduced current noise, and also confirmed the activationofsinglenanopores.Therefore, theexceptionallylownoiseandeaseof fabricationwill facilitatetheunderstandingof the fundamentalpropertyandtheapplicationof suchatomicallythinnanoporesensors.