Occurrence of Chiral Nanostructures Induced by Multiple Hydrogen Bonds.

Developing artificial systems to mimic the emergence of chirality is of vital importance in better understanding the mysterious origin of natural homochirality and guiding the design of advanced chiroptical materials. Herein, we present a DNA-inspired control over the emergence of supramolecular nanoscale chirality in multiple hydrogen-bonded self-assemblies. N-Terminated aromatic amino acids bearing serine and aromatic domains could self-assemble into lamellar microsheets without nanoscale chirality, ascribed to their pronounced molecular stacking preference on two-dimensional orientations. Significantly, when achiral bipyridine-, melamine-, and imidazole-based molecular binders that could potentially form hydrogen-bonded complexes with these aromatic amino acids were introduced, the induced chiral nanostructures from the resulting coassemblies were observed. Melamine and its derivatives presented an excellent capability to generate ordered supramolecular structures and induce the nanoscale chirality. Assisted by the key duplex hydrogen bonds between the melamine core and serine segments, chiral nanotubes and ribbons were obtained. This study reveals that multiple hydrogen bonds are the prerequisite for inducing the emergence of chiral nanostructures from integrated coassemblies.

An aza-BODIPY based near-infrared fluorescent probe for sensitive discrimination of cysteine/homocysteine and glutathione in living cells.

Discriminative detection of glutathione (GSH) from cysteine/homocysteine (Cys/Hcy) is achieved through two emission channel analysis using a stable, highly sensitive, and selective near-infrared fluorescent probe that bears 7-nitrobenzo-2-oxa-1,3-diazole and aza-BODIPY units. The probe was successfully applied for simultaneous determination of GSH and Cys/Hcy in living cells.