Anionically charged fluorescent conjugated polyelectrolytes of poly{[4,7‐(2,1,3‐benzothiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} (P1) and poly{[4,7‐(bis(thiophen‐2‐yl)benzo‐2,1,3‐thiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} (P2) were synthesized by Suzuki crosscoupling polymerization in the presence of a palladium catalyst. The conjugated polyelectrolytes with sulfonate groups, as efficient signal amplifying reporters, were carefully designed to be soluble in water over the entire pH range examined and interact with proteins through intermolecular forces. The polymers exhibited blue emission in aqueous solutions but green or red emission in solid form depending on the conjugation length due to intermolecular exciton migration. The anionic conjugated polymers exhibited blue‐to‐green or blue‐to‐red changes in fluorescence upon exposure to charged proteins, indicating that the polymers have potential applications in fluorescent array systems for protein. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

A water-soluble, sulfur-containing fluorescent conjugated polymer exhibits a visible fluorescence color change for detection of mercury in the presence of thymine. A new concept provides the design of a sensor ensemble using a simple combination method. This strategy avoids the need for complicated design and synthesis of a recognition group, eliminating the tedious synthetic efforts for the preparation of a sensor material.

Frontispiece: A simple and facile detection and removal of mercury ion in aqueous solution can be performed using sensor ensemble comprising water‐soluble conjugated polymer and thymine. Upon interacting with mercury ion, fluorescence of the ensemble shows blue‐to‐red color change. Simultaneously, mercury ion can be removed from the solution by simple filtration resulted from efficient precipitation with the ensemble. Further details can be found in the article by N. Y. Kwon, D. Kim, J. H. Son, G. S. Jang, J. H. Lee, and T. S. Lee* .

We have synthesized APBT and APTBT containing benzothiadiazole units by Suzuki cross-coupling reaction with good yield. The polymers showed blue emission colors in aqueous solutions, while long wavelength shift was observed in the solid state due to facilitated exciton migration. APBT and APTBT are water-soluble and highly-fluorescent conjugated polymers with negatively charged sulfonate side chains and thus they can be electrostatically assembled with oppositely charged polyelectrolyte such as cationic polymer, poly(dimethyldiallylammonium chloride) (PDAC) via layer-by-layer (LbL) deposition technique on a glass slide. According to the increased the number of bilayer, we found that the assembled film exhibited larger enhancement of the long wavelength emission relative to the blue emission, due to the increased excition migration.

A water-soluble hyperbranched polymer containing boronic acid groups at the ends of the polymer, which are capable of binding to diol-containing mannose, was syntheized. The hyperbranched polymer was prepared by a palladium-catalyzed Suzuki cross-coupling reaction using the tribromo monomer for the hyperbranched type structure. The water-soluble hyperbranched polymer (HP) exhibited enhanced fluorescence intensity upon exposure to lectin in the presence of mannose compared to other proteins, such as lysozyme and cytochrome c, because mannose plays a key role in binding both lectin and HP resulting in selective sensing toward lectin.