Synthetic Multivalent Glycans for the Detection of Pathogens

by Hatch, Duane M.

Current challenges to minimize health risks resulting from a potential bioterrorist attack necessitate the development of autonomous environmental monitoring systems and compact portable biosensors. Most point-of-care diagnostics use antibodies as capture and recognition elements. However, monoclonal antibodies are expensive and exhibit poor shelf life at standard operating temperatures. Unlike antibodies, cell-surface glycans are robust molecules and not prone to facile decomposition. They are natural receptors for several cellular processes such as proliferation, differentiation, migration and changes in cell shape. However, glycans have not been used as recognition motifs in biosensor technologies because of their apparent lack of selectivity. Here, we present that it is possible to tailor glycans to achieve high selectivity and sensitivity. Using a modular synthetic approach, we have synthesized a panel of high-affinity multivalent glycans for the direct detection of type 1 E. coli and the closely related Shiga Toxins (Stx1 and Stx2). Lower limits of detection were achieved with the synthetic glycans compared to commercial antibodies. These robust, synthetic recognition elements can be directly incorporated onto existing biosensor platforms.