Controlling the Hierarchical Assembly of π-Conjugated Oligoelectrolytes.

Here, a means of controlling the assembly pathways of p-conjugated oligoelectrolytes into supramolecular fibers and microtubes is presented, and it is shown how the addition of small end-caps to well-defined and pH-responsive conjugated oligomers can alter the balance between repulsive and attractive supramolecular forces and enables control of the morphology of the hierarchical assembly process. The assembly stages from nuclei to protofibers are evidenced and a hypothesis on the mechanism of microtubes formation using a combination of analytical methods is provided, revealing different degrees of order at different scales along the structural hierarchy.

Conjugated polymer shells on colloidal templates by seeded Suzuki–Miyaura dispersion polymerization.

The self-assembly of colloidal conjugated polymers presents a versatile and powerful oute towards new functional optoelectronic materials and devices. However, this strategy relies on the existence of chemical protocols to prepare highly monodisperse colloids of conjugated polymers in high yields. Here, a recently developed Suzuki–Miyaura dispersion polymerization method is adopted to synthesize core–shell particles, in which a conjugated polymer shell is grown onto non-conjugated organic and inorganic colloidal templates.

Manipulation of the local density of photonic states to elucidate fluorescent protein emission rates.

We present experiments to determine the quantum efficiency and emission oscillator strength of exclusively the emitting states of the widely used enhanced green fluorescent protein (EGFP). We positioned the emitters at precisely defined distances from a mirror to control the local density of optical states, resulting in characteristic changes in the fluorescence decay rate that we monitored by fluorescence lifetime microscopy. To the best of our knowledge, this is the first emission lifetime control of a biological emitter.