A chemosensor selection for the fluorescence identification of tryptophan (Trp) amino acids in aqueous solutions with nanomolar detection

A new disulfide-based, imine-linked fluorescent receptor 1 has been synthesized for the highly selective gratitude of tryptophan (Trp) among the all amino acids investigated in aqueous solutions via synergistic effects of intermolecular hydrogen bonding and electrostatic interactions. The photophysical properties of the receptor 1 were evaluated by UV/Vis absorption and fluorescence spectroscopic methods. Receptor 1 selectively recognized tryptophan (Trp) amino acid in DMSO/water with a detection limit down to 47.6 nM. The mechanism of binding was fully validated by computational studies. The theoretical calculations revealed the role of π-π stacking as well as hydrogen bonding in binding of tryptophan with receptor.