Vancomycin modified graphene oxide membranes with exceptional enantioseparation performances

Enantioseparation membranes generally suffer from a trade-off between permeability and enantioselectivity. However, the retarded transport membranes have great potential in overcoming this trade-off. The main objective of this work was to fabricate an effective enantioseparation membrane that can conform to the retarded transport mechanism. In this work, a macrocyclic glycopeptide antibiotic, vancomycin, was used as a chiral selector to modify the graphene oxide sheets (GOs), allowing for Van-GOs, and then GO-based membranes (GOMs) were constructed, yielding Van-GOMs. Van-GOMs display a significant increase in enantioselectivity (expressed by the separation factor) and 1-3 orders of magnitude increase in flux relative to traditional enantioseparation membranes; and meanwhile, they exhibit a moderate rise in both flux and enantioselectivity compared to amino acid- and dipeptide-modified GO-based membranes, substantiated by the fact that the separation factor-flux combinations shift to the upper right corner in the upper-bound-like plot. Our findings suggest that the suitable screening of chiral selectors plays a critical role in constructing retarded transport membranes and provides new opportunities for designing high-performance enantioseparation membranes, with a view to implementing the large-scale production of diversely enantiopure compounds.