RECOGNITION OF SUGAR BIOMARKERS VIA A FLUORESCENT PROBE BASED ON BORONIC ACID APPENDED BIPYRIDINIUM SALTS
Angel Resendez1, Dominic-Lucc Webb2, Bakthan Singaram1.
1University of California Santa Cruz, Santa Cruz, CA, 2Uppsala University, Uppsala, Uppland, SE.
Gastrointestinal barrier dysfunction is now recognized as an early event in the pathogenesis of several problematic diseases, such as inflammatory bowel disease (IBD), Parkinsonâ€™s disease, Crohnâ€™s disease, celiac disease, and type-1 and type-2 diabetes mellitus. Gastrointestinal permeability can be assessed noninvasively by analyzing saccharide biomarkers in urine such as sucrose, lactulose, mannitol, and the synthetic sweetener sucralose. Current methods for analyzing these biomarkers require expensive and time consuming instrumentation such as high performance liquid chromatography/mass spectrometry (LC/MS). An alternative approach has been taken by using a 2-component system that comprises a boronic acid substituted bipyridinium salt as the receptor and a fluorescent reporter dye in which the system operates at physiological pH. A comparative study was conducted between 2 types of boronic acid receptors (bis and mono substituted viologens) to determine their binding capabilities for the sugar biomarkers of interest. Lactulose gave the highest fluorescence recovery with a limit of detection and quantification of 80 and 500 ÂµM respectively with bis substituted boronic acid viologen. In addition to analyzing the sugar biomarkers, an analysis of various sugar alcohols was also performed to determine the discriminatory properties of the 2 receptors. This developed 2-component system demonstrates a useful tool for measuring sugars in urine with excellent stability, cost, and throughput benefits.