DNA nucleoside interaction and identification with carbon nanotubes

We investigate the interaction of individual DNA nucleosides with a carbon nanotube (CNT) in vacuum and in the presence of external gate voltage. We propose a scheme to discriminate between nucleosides on CNTs based on measurement of electronic features through a local probe such as scanning tunneling spectroscopy. We demonstrate through quantum mechanical calculations that these measurements can achieve 100% efficiency in identifying DNA bases. Our results support the practicality of ultrafast DNA sequencing using electrical measurements.