Bis(phenylethynyl)arene Linkers in Tetracationic Bis-triarylborane Chromophores Control Fluorimetric and Raman Sensing of Various DNAs and RNAs.

We report four new luminescent tetracationic bis-triarylborane DNA and RNA sensors that show high binding affinities, in several cases even in the nanomolar range. Three of the compounds contain substituted, highly emissive and structurally flexible bis(2,6-dimethylphenyl-4-ethynyl)arene linkers (3: arene=5,5'-2,2'-bithiophene; 4: arene=1,4-benzene; 5: arene=9,10-anthracene) between the two boryl moieties and serve as efficient dual Raman and fluorescence chromophores. The shorter analogue 6 employs 9,10-anthracene as the linker and demonstrates the importance of an adequate linker length with a certain level of flexibility by exhibiting generally lower binding affinities than 3-5.

Chemical Analysis of Pollen by FT-Raman and FTIR Spectroscopies.

Pollen studies are important for the assessment of present and past environment, including biodiversity, sexual reproduction of plants and plant-pollinator interactions, monitoring of aeroallergens, and impact of climate and pollution on wild communities and cultivated crops. Although information on chemical composition of pollen is of importance in all of those research areas, pollen chemistry has been rarely measured due to complex and time-consuming analyses. Vibrational spectroscopies, coupled with multivariate data analysis, have shown great potential for rapid chemical characterization, identification and classification of pollen.

Tetracationic Bis-Triarylborane 1,3-Butadiyne as a Combined Fluorimetric and Raman Probe for Simultaneous and Selective Sensing of Various DNA, RNA, and Proteins.

A bis-triarylborane tetracation (4-Ar B-3,5-Me C H )-C≡C-C≡C-(3,5-Me C H -4-BAr [Ar=(2,6-Me -4-NMe -C H ) ] (2 ) shows distinctly different behaviour in its fluorimetric response than that of our recently published bis-triarylborane 5-(4-Ar B-3,5-Me C H )-2,2'-(C H S) -5'-(3,5-Me C H -4-BAr ) (3 ). Single-crystal X-ray diffraction data on the neutral bis-triarylborane precursor 2 N confirm its rod-like dumbbell structure, which is shown to be important for DNA/RNA targeting and also for BSA protein binding. Fluorimetric titrations with DNA/RNA/BSA revealed the very strong affinity of 2 and indicated the importance of the properties of the linker connecting the two triarylboranes.

Effect of structure levels on surface-enhanced Raman scattering of human telomeric G-quadruplexes in diluted and crowded media.

Human telomeric G-quadruplexes are emerging targets in anticancer drug discovery since they are able to efficiently inhibit telomerase, an enzyme which is greatly involved in telomere instability and immortalization process in malignant cells. G-quadruplex (G4) DNA is highly polymorphic and can adopt different topologies upon addition of electrolytes, additives, and ligands. The study of G-quadruplex forms under various conditions, however, might be quite challenging.