Tunable spin-selective transport through DNA with mismatched base pairs.

In our theoretical analysis of spin-selective transport through a homogeneous poly(G)-poly(C) DNA we explore the influence of a mismatched base pair in the DNA chain. The spin polarization of the electrical current through DNA is strongly sensitive to the presence of the mispair in a DNA with less than 20 base pairs. Replacing a canonical G-C base pair by a G-A mispair in homogeneous DNA can strongly decrease, increase up to an order of magnitude, or even change the sign of spin polarization of the electrical current. The mispair induced spin-selective current through DNA also depends on the location of the mispair within the DNA.