Macromol. Rapid Commun. 9/2013

Abstract

Frontispiece: Selective quenching of the dual fluorescence from poly(fluorene) and poly(thiophene) blocks of the cationic, all‐conjugated AB diblock copolymer poly[9,9‐bis(2‐ethylhexyl)fluorene]‐b‐poly[3‐(6‐trimethylammoniumhexyl) thiophene] bromide (PF2/6‐b‐P3TMAHT) is shown to provide a sensitive and selective ratiometric method for sensing halide ions, single and double stranded DNA. It has potential for both analysis and imaging of other negatively charged species of chemical and biological interest. Further details can be found in the article by S. M. Fonseca,* R. P. Galvão, H. D. Burrows,* A. Gutacker,* U. Scherf, and G. C. Bazan .

Polymers for Luminescent Sensing Applications

“…AB diblock copolymer, P14 with hydrophobic polyfluorene and hydrophilic polythiophene blocks showed dual fluorescence from each block (Figure c) . The positively charged polythiophene block was reactive to anions.…”

“…AB diblock copolymer, P14 with hydrophobic polyfl uorene and hydrophilic polythiophene blocks showed dual fl uorescence from each block (Figure 3 c). [ 23 ] The positively charged polythiophene block was reactive to anions. On the contrary, the hydrophobic polyfl uorene block was insensitive to anions and its fl uorescence could be employed as an internal standard for anion sensing.…”

Selective recognition of biologically important anions using a diblock polyfluorene–polythiophene conjugated polyelectrolyte

“…14 Nucleotide phosphates are the smaller building blocks of large biological moieties such as DNA and are extremely important substrates in processes such as energy metabolism. 15 Previously, we and others have shown how the cationic homopolymer poly[3-(6trimethylammoniumhexyl) thiophene] bromide (P3TMAHT) undergoes electrostatic assembly with smaller, oppositelycharged species such as halide ions 16 or surfactants, 17 which leads to a change in the conformation and photoluminescence (PL) properties of the PT. The addition of a second, distinct block to the CPE chain in the form of an all-conjugated diblock copolymer may impart further sensitivity towards the polymer environment.…”

“…23,24 The shape of the aggregates formed, and thus the optical properties, were found to depend highly on the polarity of the solvent. The fact that electrostatic binding of oppositely-charged species to the PT block of this copolymer induces the subsequent change in its 16,25 The ratiometric nature of these sensing platforms results from the fact that ionic interactions between the analyte and pendent groups of the CPE block lead to selective quenching of the PT photoluminescence, while the emission of the noncomplexed PF block remains unquenched. Specific electrostatic interactions appear to play a significant role in the quenching of the PT block, suggesting that this diblock copolymer may potentially be developed as a platform sensory material for a host of anionic analytes.…”

Conjugated Polyelectrolyte (CPE) Poly{3-[6-(N-methylimidazolium)hexyl]-2,5-thiophene} Complexed with DNA: Relation between Colloidal Level Solution Structure and Chromic Effects

“…25, 26 Burrows and co-workers prepared block copolymers, thus allowing an additional energy transfer between blocks. 27 However, in addition to these trimethyl ammonium substituted materials, an increasing attention has been paid to the cationic imidazolium group through the synthesis of novel imidazolium substituted CPEs, such as arylenevinylenes where the imidazolium unit is incorporated in the main chain, 28 or polythiophenes incorporating imidazolium unit in the side chain either in copolymers 29 or block copolymers. 30 These materials are water soluble and can be used in polymer silica hybrid materials, 31 multilayers formed from layer-to-layer processes 32 and as cathode interlayers for organic solar cells.…”