A more than six orders of magnitude UV-responsive organic field-effect transistor utilizing a benzothiophene semiconductor and Disperse Red 1 for enhanced charge separation.

A more than six orders of magnitude UV-responsive organic field-effect transistor is developed using a benzothiophene (BTBT) semiconductor and strong donor-acceptor Disperse Red 1 as the traps to enhance charge separation. The device can be returned to its low drain current state by applying a short gate bias, and is completely reversible with excellent stability under ambient conditions.

Unsorted single walled carbon nanotubes enabled the fabrication of high performance organic thin film transistors with low cost metal electrodes.

Transistors with a diketopyrrolopyrrole-quarterthiophene (DPP-QT) semiconductor and low-cost Al or Cu electrodes were studied. Albeit a large charge injection resistance exists between DPP-QT and Al or Cu, the resistance was dramatically reduced when unsorted single walled carbon nanotubes (SWCNTs) were blended into the DPP-QT film. This led to a high mobility of 0.64 and 1.1 cm(2) V(-1) s(-1), respectively, for Al and Cu devices, which is similar or even better than the device using gold electrodes (0.78 cm(2) V(-1) s(-1)).

Dendronised block copolymers as potential vectors for gene transfection.

A series of block copolymers containing a dendronised cationic block for efficient DNA binding and a poly(ethylene glycol) block for encapsulation of the complex were synthesised in a modular fashion using a combination of click chemistry and ring-opening metathesis polymerisation. DNA binding experiments, investigated using gel electrophoresis, dynamic light scattering and transmission electron microscopy, showed that all polymers prepared in this study strongly complex DNA and self-assemble into polyion complex micelles with apparent hydrodynamic radii ranging from 20-120 nm at physiological pH (7.4). The in vitro transfection efficiency and toxicity of these potential non-viral vectors were also evaluated in HeLadouble dagger cells using plasmid DNA encoding for green fluorescent protein as the reporter gene.

Chiral discrimination in photochromic helicenes.

A photoresponsive dithienylethene derivative bearing chiral pinene-based arms underwent a stereoselective photoinduced cyclization reaction to produce greater than 98% of a single diastereomer. The magnitude of the optical rotation changed as much as Delta[alpha]373 = 8698 degrees upon alternate irradiation with 400 nm and greater than 434 nm light.