Discrimination of Saccharides with a Fluorescent Molecular Imprinting Sensor Array Based on Phenylboronic Acid Functionalized Mesoporous Silica

A fluorescent indicator-displacement molecular imprinting sensor array based on phenylboronic acid functionalized mesoporous silica was developed for discriminating saccharides. D-Fructose imprinted material (FruIM), Dxylose imprinted material (XylIM) together with a control blank nonimprinted material (NIM) were synthesized as the elements of the imprinting sensor array. Spectrofluorimetric titrations of the three materials with eight selected saccharides were carried out, and Stern-Volmer quenching constants (K-sv) of NIM, FruIM, and XylIM with the eight selected saccharides were obtained to investigate the interaction of the materials with saccharides. The present approach couples molecular imprinting technique to indicator-displacement strategy with the use of one conventional saccharide receptor (phenylboronic acid) and one commercially available fluorescent dye (Alizarin Red S., ARS) as the indicator, and allows identifying two template saccharides (D-fructose and D-xylose) plus eight nontemplate saccharides (D-arabinose, D-glucose, D-galactose, D-mannose, L-sorbose, D-ribose, L-rhamnose and sucrose). The principal component analysis (PCA) plot shows a clear discrimination of the 10 tested saccharides at 100 mM and the first principal component possesses 94.8% of the variation. Besides, the developed saccharide imprinted sensor array is successfully applied to discriminating three brands of orange juice beverage.