Chiral metal–organic framework coated quartz crystal microbalance for chiral discrimination

Abstract

The development of novel methods for chiral discrimination remains a challenging and important area due to the structural similarity but significantly different roles of enantiomers in biological and environmental systems. Here we report a 3D chiral porous Zn–organic framework (Zn₂(bdc)(L-lac)(dmf)·DMF) coated quartz crystal microbalance (QCM) sensor for chiral discrimination of four pairs of enantiomers. The adsorption isotherms of the enantiomers on Zn₂(bdc)(L-lac)(dmf)·DMF follow the Dubinin–Astakhov equation. The QCM sensor shows excellent sensitivity and enantioselectivity. The chiral recognition ability of the Zn₂(bdc)(L-lac)(dmf)·DMF sensor was temperature and concentration dependent. The chiral selectivity factor ranged from 1.36 (S/R-1-(1-naphthyl)ethylamine) to 2.20 (S/R-1-phenylethylamine) at 25 °C. The good chiral recognition capacities of enantiomers provide Zn₂(bdc)(L-lac)(dmf)·DMF potential for the discrimination of enantiomers.