: Deep Eutectic Solvents with Bio-Based Chiral HBD or HBA: a New Electroanalytical Approach for the Enantiodiscrimination of Chiral Probes.

Deep Eutectic Solvents (DESs) offer advantages similar to Ionic Liquids (ILs), but with easier and more sustainable synthesis; moreover, bio-based DESs often include chiral components, surprisingly underexploited. Herein we intent to present the use of enantiopure DESs as chiral media for enantioselective electroanalysis. Three chiral DESs, consisting in a molecular salt with bio-based chiral cation [NopolMIm]+ combined with three natural and low-cost partners (levulinic acid, glycerol and urea), are introduced and investigated as chiral voltammetry media [1]. Significant potential differences were observed for the enantiomers of a model chiral probe, also changing the achiral partner and reaching an impressive ~0.5 V in the levulinic acid case. With the same medium good enantiodiscrimination was also observed for the aminoacid tryptophan, a quite different probe of applicative interest [1]. Such proof-of-concept results also suggest many interesting developments, including a deeper investigation of the molecular interactions within the three-actors (probe and the two DES components: HBD and HBA) system, as such and at the interphase with the charged electrode surface, and a further analysis of the role of acid/base interactions. For this reason, many other chiral DESs (with different HBD and HBA, and in different ratios) were studied, considering the effect of the water amount in the enantioselection ability. These findings can be considered as a remarkable step further in chiral electroanalysis as well as in the development of task-specific enantioselective media.