posted on 2007-11-07, 00:00authored byNicola Y. Edwards, Thomas W. Sager, John T. McDevitt, Eric V. Anslyn
The advent of the alternative sweeteners market has signaled a demand for chemosensors which
target multiple saccharides and saccharide derivatives, in aqueous media at physiological pH. This demand
has largely been unmet as existing molecular receptors for saccharides have generally not shown sufficient
degrees of affinity and selectivity in aqueous media. A chemosensor array for saccharides and saccharide
derivatives, fully operational in aqueous media at physiological pH, has been developed and is reported
herein. Boronic acid based peptidic receptors, derived from a combinatorial library, served as the cross-reactive sensor elements in this array. The binding of saccharides to these receptors was assessed
colorimetrically using an indicator uptake protocol in the taste-chip platform. The differential indicator uptake
rates of these receptors in the presence of saccharides were exploited in order to identify patterns within
the data set using linear discriminant analysis. This chemosensor array is capable of classifying disaccharides
and monosaccharides as well as discriminating compounds within each saccharide group. Disaccharides
have also been distinguished from closely related reduced-calorie counterparts. This linear discriminant
analysis set was then employed as a training set for identifying a specific saccharide in a real-world beverage
sample. The methodology developed here augers well for use in other real-world samples involving
saccharides as well as for sensing other desired analytes.