The free and protein-bound tryptophan (Trp) sensing ability of an alanyl-(4,6-O-ethylidene-β-D-glucopyranosylamine) derived chiral receptor (L-N2O2) has been explored using UV-vis absorption, fluorescence and mass spectroscopy. L-N2O2 decreases the intrinsic emission intensity of Trp at 360 nm via a static quenching mechanism, revealing the interactions between the two.