Solvent mediated thermodynamically favorable helical supramolecular self-assembly: recognition behavior towards achiral and chiral analytes

Herein, we successfully developed an entropically favored helical supramolecular self-assembly from a triphenylamine-based derivative 4 in a green solvent in order to mimic the structural transformations that occur during the self-assembly of proteins/peptides which may cause various neurodegenerative diseases. Its structural transformation from helical supramolecular self-assembly to a random coil and then achiral nanorods was studied by varying the concentration of achiral stimuli (i.e., Fe²⁺ ions). The driving force of this transformation is the strong binding affinity of chiral supramolecular assemblies and Fe²⁺ ions. Furthermore, the “metal-free” helical supramolecular self-assembly exhibited enantioselectivity for differentiating between l- and d-proline; this was achieved through a chiral stimuli-induced structural modulation methodology. Our evaluation of the effects of achiral/chiral stimuli is also novel.