DNA: Comparative Electrostatic Force Microscopy of Tetra‐ and Intra‐Molecular G4‐DNA (Adv. Mater. 29/2014)

Two forms of G4-DNA, with parallel and pairwise anti-parallel strands, are studied using atomic force microscopy by D. Porath, A. B. Kotlyar, and co-workers on page 4981. The directionality of the strands affects the molecules' structural properties and their electrical polarizability. Parallel G4-DNA is twice as polarizable as anti-parallel G4-DNA, suggesting it is a better electrical wire for bio-nanoelectronics. These results provide evidence that supports the idea that directionality of the strands may affect conformation, and consequently π–π stacking and charge mobility along the molecule. They also support the existence of delocalized states in tetra-molecular G4-DNA.