Fabrication of a Carbon Chain Based Nanosensor for Maximizing Spatial Resolution in DNA Sequencing

Using a carbon chain as the sensing element can significantly improve the spatial resolution in nanodevice based single molecule DNA sequencing. In this report, we demonstrate a top-down approach to reduce a single monolayer graphene attached to a silicon microelectrode chip to a sub-nanometer wide carbon chain suitable for DNA sequencing. This approach consists three major processing steps to first transfer the graphene to the chip, dice the attached graphene into graphene nanoribbons using Focused Ion Beam (FIB), and finally reduce the ribbon width by knocking off carbon atoms on the ribbon edge using Transmission Electron Microscopy (TEM). A final carbon chain of 0.8 nm wide and 5 nm long is accomplished. The measured electrical properties of the reduced graphene agree well with previous studies.