Carbohydrate- and Chain Length-Controlled Complexation of Carbon Nanotubes by Glycopolymers

Abstract

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.

Glycopolymer-Wrapped Carbon Nanotubes Show Distinct Interaction of Carbohydrates With Lectins

“…Particularly, SWCNTs as a model system of quasi-one-dimensional nanostructures have been utilized for selective interactions with chiral amino acids, carbohydrates, and specific proteins and nucleic acids both in vitro and in vivo due to their exceptional optical and physiochemical properties and highly tunable surface chemistry ( Reuel et al, 2011 ; Harvey et al, 2019 ; Santos et al, 2021 ; Yaari et al, 2021 ; De los). Helical wrapping of SWCNTs by natural polysaccharides and synthetic glycopolymers is an effective approach to preserve nanotube properties while stabilizing tubes in an aqueous environment ( Star et al, 2002 ; Hasegawa et al, 2004 ; Dohi et al, 2006 ; Cantwell et al, 2020 ). In addition to van der Waals attractions and hydrophobic interactions between the hydrophobic faces of the pyranose rings and the hydrophobic surface of nanotubes, intra- and inter-molecular hydrogen bonds of carbohydrates with neighboring sugar units and water molecules further stabilize the helical conformation of polymers on the surface of nanotubes ( Çarçabal et al, 2005 ; Bristol et al, 2020 ; Liu et al, 2012 ).…”

“…We have previously reported the creation of stable and water-soluble glycopolymer-wrapped single-wall carbon nanotubes (Glyco-SWCNTs) through the noncovalent complexation of nanotubes with polymers, where the interaction of glycopolymers with SWCNTs is strongly dependent on the carbohydrate identity, ligand density, and the polymer chain length ( Cantwell et al, 2020 ). Synthetic glycopolymers with highly tunable carbohydrate structures are chemically stable and can be used as glycoconjugate mimetics for many biological applications ( Sun 2018 ; Chan et al, 2020 ).…”

“…The multivalency of glycopolymers together with the tunability in polymer chain length, ligand composition and density, flexibility, and conformation promotes strong carbohydrate-mediated interactions with lectins ( Kumar et al, 2011 ; Narla et al, 2012 ; Miura et al, 2016 ; Tang et al, 2017 ). Additionally, the wrapping of SWCNTs by less-flexible disaccharide lactose-containing glycopolymers produces stable complexes in aqueous environment while preserving the intrinsic optical, electronic, and physiochemical properties of nanotubes ( Cantwell et al, 2020 ). Particularly, Glyco-SWCNT complexes fluoresce in the near-infrared (NIR) spectral regime, where attenuated tissue autofluorescence and deep tissue penetration occur in biological samples ( Weisman and Bachilo 2003 ; Lin and Weisman 2016 ).…”

Fabrication of MWCNTS‐functionalized SA pervaporation composite membranes to enhance esterification

“…The serious aggregation of carbon nanotube makes it difficult to manipulate and combine with polymers 18 and the strong hydrophobicity affects membrane selectivity. Therefore, the hydrophilicity of multi‐walled carbon nanotubes should be improved 19,20 . The dispersibility of the functionalized carbon nanotubes obtained by carboxylation surface modification and ultrasonic interruption is significantly improved.…”

“…Therefore, the hydrophilicity of multi-walled carbon nanotubes should be improved. 19,20 The dispersibility of the functionalized carbon nanotubes obtained by carboxylation surface modification and ultrasonic interruption is significantly improved. Functional modification of carbon nanotubes can solve the problem of serious aggregation and strong hydrophobicity.…”