Glycan-functionalized Polymers and Biosensors

Glycan-funtionalized gold chip as biosensor L. & F. Biomaterialien

A grafted glycopolymer brush is obtained by modifying a solid silica surface via controlled polymerization using N-acetylglucosamine (GlcNAc) in collaboration with DWI Leibniz-Institut fr Interaktive Materialien. Monomeric GlcNAc is elongated to repetitive N-acetyllactosamine (LacNAc) units by applying appropriate enzymes (glycosyltransferases). The multivalent and glycan-presenting silico surfaces function as recognition platform for several lectins including Griffonia simplicifolia lectin (GS-II) and Erythrina cristagalli lectin (ECL).

According to this technology, gold surfaces were modified in cooperation with the Institute of Materials in Electrical Engineering. The brush length was controlled by the duration of polymerization and evaluated by atomic force microscopy. The GlcNAc-residues are specifically converted by a β4-galactosyl- and a α3-galactosyltransferase to a clinically important glycosylation motif (Galili or α3-Gal epitope). This multivalent gold chip enables the binding analysis of bacterial toxin A from Clostridium difficile (TcdA) via electrochemical impedance spectroscopy and functions thereby as a biosensor (J. Lazar et al. (2015), H. Park et al. (2015)).