RESUMO
Fluorinated benzosiloxaboroles-silicon congeners of benzoxaboroles, were synthesized and tested as molecular receptors for mono- and disaccharides. The receptors differed in the Lewis acidity of the boron center as well as in the number of potential binding sites. The calculated stability constants indicated different binding affinity of benzosiloxaborole derivatives towards selected saccharides, enabling their classification using a receptor array-based sensing. Unique fluorescence fingerprints were created on the basis of competitive interactions of the studied receptors with both Alizarin Red S (ARS) and tested saccharide molecules. Detailed chemometric analysis of the obtained fluorescence data (based on partial least squares-discriminant analysis and hierarchical clustering analysis) provided the differential sensing of common saccharides, in particular the differentiation between glucose and fructose. In addition, DFT calculations were carried out to shed light on the binding mechanism under different pH conditions.
Assuntos
Carboidratos/análise , Fluorescência , Frutose/análise , Glucose/análise , Compostos de Boro , Compostos Bicíclicos Heterocíclicos com PontesRESUMO
Gold electrodes were functionalized with thiolated phenylboronic acids or by sequential immobilization of alkanethiols with terminal carboxylic groups and conjugation with aminophenylboronic acids. The stepwise assembly of organic molecules was characterized by several voltammetric techniques with systematic monitoring of surface coverage of organic molecules anchored to the gold electrodes. The receptor properties and applicability of the obtained monomolecular layers for the voltammetric detection of fructose and fluoride ions in solution were evaluated. The MPBA and APBA modified electrodes can be applied for the voltammetric determination of chosen non-electroactive analytes on the basis of the changes in peak currents of ferricyanide/ferrocyanide couple in the presence of the detected species.