Water-soluble low-molecular-weight cellulose chains radially oriented on gold nanoparticles

Abstract

Cellulose chains bearing N-lipoyl group at the reducing-end as a sulfide linker, self-assembled on the surface of gold nanoparticles (CELL2Au, CELL13Au, and CELL41Au with the number average degrees of polymerization (DP n ) of 2, 13, and 41, respectively) were prepared. CELL2Au, CELL13Au, and CELL41Au were obtained via deprotection of the cellulose triacetate (CTA) self-assembled on the surface of gold nanoparticles that are consisting of CTA chains with corresponding DP n organized in a radial manner with head-to-tail orientation, where a head is the reducing-end, and a tail is the nonreducing-end. CELL2Au and CELL13Au were welldispersed in water including a trace of methanol, whereas CELL41Au was not. The transmission electron microscopy (TEM) observation of CELLAus deposited on copper grids revealed that the diameters (d) of the gold cores of CELL2Au, CELL13Au, and CELL41Au were 6.1, 6.1, and 11.5 nm, respectively. Wide angle X-ray diffractgram showed that cellulose chains of CELL13Au had quite low crystallinity and exhibited additional faint diffraction pattern of cellulose II. Cellulose chains of CELL41Au were amorphous. The UV-vis measurements revealed that CELL2Au and CELL13Au were well-dispersed in water. The hydrodynamic diameters (D) of CELL2Au and CELL13Au in water were 21.8 and 55.9 nm, respectively, according to dynamic light scattering (DLS) measurements, suggesting that cellulose chains on the gold were organized in a radial manner with head-to-tail orientation. 1 H-NMR measurement revealed that low-molecular-weight cellulose chains (DP n = 13) on the gold dissolved in water, whereas low-molecular-weight cellulose (DP n = 13) itself did not.

Coating matters: the influence of coating materials on the optical properties of gold nanoparticles

“…This method is known as the LbL (Layerby-Layer) technique [87] , and is widely applied not only to stabilize gold nanoparticle dispersions, but also to confer them with a desired surface charge, which is determined by the charge of the outmost polyelectrolyte layer [85]. Besides synthetic charged polymers, also bio-polymers [88] such as DNA [89 -93] , dextran [94] , cellulose [95,96] , chitosan [97,98] and various peptides and proteins can adsorb onto the nanoparticle surface, and have been widely used to make gold nanoparticles suitable for bio-applications. Moreover, polyelectrolyte multilayers can also serve as primers to make gold nanoparticles suitable for further surface modifi cations or coatings, such as silica [99] or pNIPAM microgels [100] .…”

Synthesis of blockwise alkylated tetrasaccharide–organic quantum dot complexes and their utilization for live cell labeling with low cytotoxicity

“…The layer of the blockwise alkylated tetrasaccharides (shell) and QDs (core) are included as the hydrodynamic diameter. We have reported water-soluble low molecular weight cellulose chains radially oriented on gold nanoparticles (Enomoto-Rogers et al 2011). In this previous article, we have described that hydrodynamic diameters of gold nanoparticles covered by cellulose chains include those of gold core and cellulosic shell, confirmed by transmission electron microscopic observation.…”

Confronting the Challenge of Cellulose Molecular Weight Measurement: An Accurate, Rapid, and Universal Method with Ionic Liquid as an Additive

“…3−7 For example, Enomoto-Rogers et al found that cellulose with different degrees of polymerization (DP) selfassembled on the surface of gold nanoparticles exhibiting different dispersibilities in water. 3 Xie et al reported that the molecular weight of cellulose affected its entanglement, orientation, and crystallization, which had a great impact on the mechanical properties of the cellulose fiber. 4 Munster et al regulated the drug release process by changing the molecular weight of oxidized cellulose.…”

“…As the most abundant natural polymer, cellulose has been widely used in the fields of textile, food, biology, energy, and advanced materials. , The molecular weight of cellulose materials significantly affects their properties, such as solubility, mechanical properties, rheological properties, and crystallization behavior. − For example, Enomoto-Rogers et al found that cellulose with different degrees of polymerization (DP) self-assembled on the surface of gold nanoparticles exhibiting different dispersibilities in water . Xie et al reported that the molecular weight of cellulose affected its entanglement, orientation, and crystallization, which had a great impact on the mechanical properties of the cellulose fiber .…”