Organic thin‐film transistors modified with 15‐base PNA strands are used for the selective detection of target DNA sequences. These simple devices provide a low‐cost, label‐free and in situ detection platform with excellent discrimination between single and double base mismatches in the target DNA sequence. The electronic detection signal is corroborated with conventional optical methods, displaying similar hybridization parameters.

The development of organic transistors for flexible electronics requires the understanding of device behavior upon the application of strain. Here, a comprehensive study of the effect of polymer‐dielectric and semiconductor chemical structure on the device performance under applied strain is reported. The systematic change of the polymer dielectric results in the modulation of the effects of strain on the mobility of organic field‐effect transistor devices. A general method is demonstrated to lower the effects of strain in devices by covalent substitution of the dielectric surface. Additionally, the introduction of a hexyl chain at the peripheries of the organic semiconductor structure results in an inversion of the effects of strain on device mobility. This novel behavior may be explained by the capacitative coupling of the surface energy variations during applied strain.

Sensors based on organic field‐effect transistors (OFETs) must overcome challenges in reproducibility, sensitivity, and selectivity. Here we describe an approach to increase the sensitivity and induce selectivity within an existing (OFET) through the incorporation of an evaporated sensor layer based on a calix[n]arene molecule. The mild method does not influence device properties, and is amendable to incorporation into reproducible, commercial transistors.

Graphene, laterally confined within narrow ribbons, exhibits a bandgap and is envisioned as a next-generation material for high-performance electronics. To take advantage of this phenomenon, there is a critical need to develop methodologies that result in graphene ribbons o10 nm in width. Here we report the use of metal salts infused within stretched DNA as catalysts to grow nanoscopic graphitic nanoribbons. The nanoribbons are termed graphitic as they have been determined to consist of regions of sp 2 and sp 3 character. The nanoscopic graphitic nanoribbons are micrometres in length, o10 nm in width, and take on the shape of the DNA template. The DNA strand is converted to a graphitic nanoribbon by utilizing chemical vapour deposition conditions. Depending on the growth conditions, metallic or semiconducting graphitic nanoribbons are formed. Improvements in the growth method have potential to lead to bottom-up synthesis of pristine single-layer graphene nanoribbons.

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