The idea is that individual base pairs (the four chemical "letters" of the DNA alphabet) can then be read off one at a time as they pass through the nanopore.

Instead an enzyme, called an exonuclease, is attached to the top of the AHL. It cleaves individual base pairs from the DNA strand and feeds them through the pore to be detected one at a time.

I base this conclusion not on any individual study, but on large-scale and systematic reviews of thousands of studies conducted in every major English-speaking country.