Glycans are ubiquitous and essential biomolecules with diverse biological functions, including maintenance of cell structure, signal transduction, and cellular interactions. Furthermore, aberrant glycosylation is implicated in a wide range of human diseases, such as cancer, neuronal disease, and diabetes. However, further progress in glycan-related research and therapeutic application is significantly limited by the lack of analytical tools capable of recognizing these structurally diverse biomolecules with high affinity and specificity. Glycans are poorly immunogenic, hindering development of highly selective anti-glycan antibodies. Lectins have been used for recognition and purification of glycosylated biomolecules, but lectins have a very limited epitope range and modest affinity for carbohydrates. Therefore, there exists a strong need to develop reagents capable of binding glycans with high specificity and affinity.