Direct synthesis of molecularly imprinted nanozymes with a biomimetic catalytic motif for glycosidic bond cleavage

Carbohydrates are the most abundant organic molecules on Earth and play essential roles in biology. Natural glycosidases cleave glycosidic linkages using a pair of conserved carboxylic acid residues. Here we report the direct synthesis of nanozymes that mimic glycosidases through molecular imprinting of thiosemicarbazide-derived glycan templates, prepared in one step from unprotected mono- or oligosaccharides. The thiosemicarbazide group binds strongly to a dicarboxylic acid functional monomer (FM), enabling installation of the double-acid catalytic motif into the imprinted active site. The resulting nanozymes cleave glycosidic bonds in oligo- and polysaccharides (e.g., cellobiose and cellulose) by a mechanism analogous to retaining glycosidases. Molecular imprinting also allows the active site to accommodate a single or predefined number of sugar residues, tuning both the size of the pocket and the distance between binding and catalytic groups, thereby enabling rational control of the cleavage site along the substrate.