“…In these respects, DNA electron transfer (ET) follows many studies of ET through proteins in solution, 31,32 twodimensional films at pure and modified electrode surfaces, 33−36 and at the single-molecule level of functional ET proteins. 35−38 As for protein ET, views on DNA conductivity rest on concepts from molecular ET science 39,40 such as superexchange, "vibrationally assisted tunnelling" or "hopping" between DNA base pairs, 41,42 and concepts of small and large polarons. 14,15 In comparison with proteins, DNA-based molecular electronic conductivity displays, however, differences which are only partly understood, notably:…”