Stable dispersions of single-wall carbon nanotubes (SWCNTs) by biopolymers in an aqueous environment facilitate their potential biological and biomedical applications. In this report, we investigated a small library of precision synthesized glycopolymers with monosaccharide and disaccharide groups for stabilizing SWCNTs via noncovalent complexation in aqueous conditions. Among the glycopolymers tested, disaccharide lactose-containing glycopolymers demonstrate effective stabilization of SWCNTs in water, which strongly depends on carbohydrate density and polymer chain length as well. The introduction of disaccharide lactose potentially makes glycopolymers less flexible as compared to those containing monosaccharide and facilitates the wrapping conformation of polymers on the surface of SWCNTs while preserving intrinsic photoluminescence of nanotubes in the near-infrared region. This work demonstrates the synergistic effects of the identity of carbohydrate pendant groups and polymer chain length of glycopolymers on stabilizing SWCNTs in water, which has not been achieved previously.

We report a straightforward synthesis of aryl azide chain-end functionalized N-linked glycan polymers and its application for affinity-assisted photo-labelling of specific protein.

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Glyconanomaterials with unique nanoscale property and carbohydrate functionality show vast potential in biological and biomedical applications. We investigated the interactions of noncovalent complexes of single-wall carbon nanotubes that are wrapped by disaccharide lactose-containing glycopolymers with the specific carbohydrate-binding proteins. The terminal galactose (Gal) of glycopolymers binds to the specific lectin as expected. Interestingly, an increased aggregation of nanotubes was also observed when interacting with a glucose (Glc) specific lectin, likely due to the removal of Glc groups from the surface of nanotubes resulting from the potential binding of the lectin to the Glc in the glycopolymers. This result indicates that the wrapping conformation of glycopolymers on the surface of nanotubes potentially allows improved accessibility of the Glc for specific lectins. Furthermore, it shows that the interaction between Glc groups in the glycopolymers and nanotubes play a key role in stabilizing the nanocomplexes. Overall, our results demonstrate that nanostructures can enable conformation-dependent interactions of glycopolymers and proteins and can potentially lead to the creation of versatile optical sensors for detecting carbohydrate-protein interactions with enhanced specificity and sensitivity.