Enantiorecognition of a chiral analyte usually requires
the ability
to respond with high specificity to one of the two enantiomers of
a chiral compound. However, in most cases, chiral sensors have chemical
sensitivity toward both enantiomers, showing differences only in the
intensity of responses. Furthermore, specific chiral receptors are
obtained with high synthetic efforts and have limited structural versatility.
These facts hinder the implementation of chiral sensors in many potential
applications. Here, we utilize the presence of both enantiomers of
each receptor to introduce a novel normalization that allows the enantio-recognition
of compounds even when single sensors are not specific for one enantiomer
of a target analyte. For this purpose, a novel protocol that permits
the fabrication of a large set of enantiomeric receptor pairs with
low synthetic efforts by combining metalloporphyrins with (R,R)- and (S,S)-cyclohexanohemicucurbit[8]uril is developed. The potentialities
of this approach are investigated by an array of four pairs of enantiomeric
sensors fabricated using quartz microbalances since gravimetric sensors
are intrinsically non-selective toward the mechanism of interaction
of analytes and receptors. Albeit the weak enantioselectivity of single
sensors toward limonene and 1-phenylethylamine, the normalization
allows the correct identification of these enantiomers in the vapor
phase indifferent to their concentration. Remarkably, the achiral
metalloporphyrin choice influences the enantioselective properties,
opening the way to easily obtain a large library of chiral receptors
that can be implemented in actual sensor arrays. These enantioselective
electronic noses and tongues may have a potential striking impact
in many medical, agrochemical, and environmental fields.