Abstract
Carbohydrate microarrays represent powerful tools to study and detect carbohydratebinding proteins, pathogens or cells. In this paper, we report two original oximebased methods to prepare surfaces displaying well-defined structures and valency in a given microspot with improved recognition potency with lectins. In a first “direct” approach, fully synthetic aminooxylated glycoclusters have been coated onto aldehyde-activated SiO$_2$ (silicium substrate doped with 50 nm thermic oxide layer). To improve the preparation of the microarray in term of rapidity and simplicity and to provide addressable surfaces on which sugars can be linked chemoselectively as clusters at defined plots, a second “indirect” strategy has been developed using successive oxime ligation steps. In both cases, binding assays with labelled lectins have revealed more potent and selective interaction due to the clustered presentation of sugars. The observed differences of interaction have been confirmed in solution by ITC.