Aggregated Behaviors, Morphology Of Polysaccharides Molecules Studied By Atomic Force Microscopy, And Preparation Of Polysaccharides/quantum Dots Multilayer Films

In present study atomic force microscopy(AFM) was used to characterize the locust bean galactomannan(LBG) and sophora bean galactomannan(SBG) in air, in order to obtain the topography of the polysaccharides at different conditions, there were three sample preparation methods are investigated about this two kinds of polysaccharides.As for LBG through varying the polysaccharides concentrations, chemically modified surface of substrate and drying the sample in higher ambient temperature. The results indicated when conditions of preparing samples are changed, the rheological performances of the polysaccharides were also changed. Aggregated and non-aggregated microstructures were visualized. The aggregated polysaccharides exhibited many kinds of fractal structures. Even the extended single molecule was visualized successfully in which the height or diameter, width of the molecule were calculated. As for SBG, two kinds of surfactant were used to make the polysaccharide dissolved, one is Tween-20, a non-ion surfactant, the other is tetramethylammonium (TMA), a positive-ion surfactant. Like LBG, there exist aggregated and non-aggregated microstructures, and arised a side-by-side aggregated phenomenon. The height or diameter, width of extended single molecule was calculated too. But compare to the LBG, no fractal structures were detected, the rheological performances of LBG are more fruitful than SBG All results will afford very useful information for applying the galactomannan in food science and other fields, and in experimental aspect provide an important reference for visualizing other polysaccharides.In this paper the formation of a new kind of biocompatible film (three layers) based on Hyaluronan biotin sodium salt (bHA) and streptavidin -quantum dots (sa-QDs) by alternate deposition of bHA and sa-QDs was investigated too. atomic force microscopy, UV-Vis absorption spectroscopy, and fluorescence spectroscopy were used to analyze the different aspects of the buildup process such as spectrums after a new sa-QDs adsorption, the overall surface charge of the film, and its...