The molecule-electrode interface in single-molecule transistors

What's in the middle matters little! Differential conductance measurements made on single-molecule rotaxanes and their precursor dumbbells in transistors with platinum electrodes reflect the molecule-electrode contacts rather than the middle section of the molecules (see diagram; the color reflects the conductance, with dark corresponding to zero current). Interface states dominate electron transport. Molecular signatures are masked and even constitutional asymmetry in the molecule is difficult to detect.