DNA as supramolecular scaffold for functional molecules: progress in DNA nanotechnology.

Oligonucleotides have recently gained increased attraction as a supramolecular scaffold for the design and synthesis of functional molecules on the nanometre scale. This tutorial review focuses on the recent progress in this highly active field of research with an emphasis on covalent modifications of DNA; non-covalent interactions of DNA with molecules such as groove binders or intercalators are not part of this review. Both terminal and internal modifications are covered, and the various points of attachment (nucleobase, sugar moiety or phosphodiester backbone) are compared. Using selected examples of the recent literature, the diversity of the functionalities that have been incorporated into DNA strands is discussed.

Fluorescent hydrogel formation from carboxyphenyl-terpyridine.

We report the analysis of a novel terpyridine based supramolecular hydrogel which shows fluorescent properties in the gel but not in the sol form; the gel forms in a narrow pH range in aqueous solutions specifically in the presence of sodium ions, and contains between 98% and 99.2% water.