Repurposing DNA-binding agents as H-bonded organic semiconductors

Organic semiconductors are usually polycyclic aromatic hydrocarbons and their analogs containing heteroatom substitution. Bioinspired materials chemistry of organic electronics promises new charge transport mechanism and specific molecular recognition with biomolecules. We discover organic semiconductors from deoxyribonucleic acid topoisomerase inhibitors, featuring conjugated backbone decorated with hydrogen-bonding moieties distinct from common organic semiconductors. Using ellipticine as a model compound, we find that hydrogen bonds not only guide polymorph assembly, but are also critical to forming efficient charge transport pathways along π−conjugated planes when at a low dihedral angle by shortening the end-to-end distance of adjacent π planes. In the π−π stacking and hydrogen-bonding directions, the intrinsic, short-range hole mobilities reach as high as 6.5 cm²V⁻¹s⁻¹ and 4.2 cm²V⁻¹s⁻¹ measured by microwave conductivity, and the long-range apparent hole mobilities are up to 1.3 × 10^–3 cm²V⁻¹s⁻¹ and 0.4 × 10^–3 cm²V⁻¹s⁻¹ measured in field-effect transistors. We further demonstrate printed transistor devices and chemical sensors as potential applications.