Ultrafine Graphene Nanomesh with Large On/Off Ratio for High‐Performance Flexible Biosensors

Graphene is an attractive material for flexible electronics and biosensors, yet its zero bandgap nature has limited the on/off ratio of field‐effect transistors (FETs) and the sensitivity of biosensors based on graphene. Graphene nanomesh (GNM), a continuous 2D graphene nanostructure with a high density of holes punched in the basal plane, has been created to introduce lateral confinement and enable improved on/off ratio. However, the GNMs produced to date typically have a relatively large dimension (constriction neck width >5 nm) and low on/off ratio (≈100) limited by the resolution of the lithography process used. Here, the exploration of a directly grown mesoporous silica template is reported for the preparation of ultrafine GNMs with considerably narrower neck width (