Single chain versus single aggregate spectroscopy of conjugated polymers. Where is the border?

Single chains of conjugated polymers e.g. MEH-PPV (poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) have become interesting objects for single molecule spectroscopy (SMS) studies.

Alignment of a conjugated polymer onto amyloid-like protein fibrils.

The amyloid-like fibril is a biomolecular nanowire template of very high stability. Here we describe the coordination of a conjugated polyelectrolyte, poly(thiophene acetic acid) (PTAA), to bovine insulin fibrils with widths of <10 nm and lengths of up to more than 10 microm. Fibrils complexed with PTAA are aligned on surfaces through molecular combing and transfer printing.

Modification of the nanoscale structure of the J-aggregate of a sulfonate-substituted amphiphilic carbocyanine dye through incorporation of surface-active additives.

The amphiphilic dye 3,3'-bis(2-sulfopropyl)-5,5',6,6'-tetrachloro-1,1'-dioctylbenzimidacarbocyanine (C8S3) self-aggregates in aqueous solution to form tubular J-aggregates with a diameter of 17.0 +/- 0.5 nm, a wall thickness of approximately 4 nm, and a length exceeding several hundred nanometers.

Host matrix dependent fluorescence intensity modulation by an electric field in single conjugated polymer chains.

An electric field oscillating at a frequency approximately 1 Hz is found to induce strong modulation of the fluorescence intensity of single poly[2-methoxy,5-(2'-ethyl-hexyloxy)-p-phenylene vinylene] (MEH-PPV) molecules (MW approximately 10(6)) embedded in a poly(methyl methacrylate) (PMMA) matrix. The MEH-PPV polymer chains are carefully isolated from the electrodes to avoid effects of injection. In a polystyrene matrix, fluorescence intensity modulations are on average much less pronounced.