A method for sequencing a nucleic acid strand, comprising the steps of: providing a solution containing truncated strands having lengths different from one another terminating with a respective dideoxynucleotide from among ddATP, ddTTP, ddGTP, and ddCTP; functionalizing first masses by a donor molecule and second masses by an acceptor molecule such as to generate a light emission when they come into mutual contact; coupling a first mass to a first end of each truncated strand; coupling the second masses to a respective terminal dideoxynucleotide of each strand; applying an AC electrical field having variable frequencies that are such as to generate, on each second mass, a net movement directed towards the first mass; acquiring a plurality of light radiations for each frequency value; and associating each light radiation acquired to a respective dideoxynucleotide and, thus, to a respective nucleotide base.