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The solvation of sugars in aqueous media matters in the understanding of biological systems and carbohydrate transformations. The presence of NaCl is known to perturb hydrogen bonding of sugar hydrates, however, direct evidence to elucidate mechanism at atom level is very rare even though the "NaCl Effect" was well known in biomass transformations for chemicals/biofuels. Here we report experimental evidences of a clear staircase‐like correlation between induced 1H NMR changes of D‐glucose/fructose with concentration of NaCl aqueous solution at room temperature; and two stable bonding status was observed in the system. HDO in sugar/NaCl aqueous solution as a "dynamic" reference is a key to enable decoupling the global salt effect in this 1H NMR investigation of NaCl‐saccharide interaction. Via a further half‐quantitative study, three structures of stable sugar‐NaCl‐water complexes were mapped for the first time in tackling the NaCl‐monosaccharide interaction at atomic level in an aqueous solution. Based on the maximum of induced 1H NMR shifts, an ideal NaCl usage was proposed. [ABSTRACT FROM AUTHOR]

Photoluminescent behaviours of chitosan were investigated. Photoluminescence can be observed from aqueous solution of chitosan, and CO[sub 2] treatment can improve the intensity of photoluminescence. The maximum emission is obtained with an excitation at ~336 nm, and the emission wavelength is dependent on the excitation wavelength with a longer excitation wavelength leading to a longer emission wavelength. The chemistry of chitosan before and after CO[sub 2] treatment was characterised; and the results reflect that carbamato anion is formed via the reaction between the amines and CO[sub 2], and is the fluorophore of the photoluminescence observed. Furthermore, chitosan was applied as an imaging agent for imaging MCF-7 cells using confocal microscopy. Blue and bright green imaging of the cells can be obtained via tuning the excitation and emission wavelength. Together with a low cytotoxicity reflected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide evaluation, fluorescent chitosan is promising for bio-imaging. [ABSTRACT FROM AUTHOR]