Cell walls, representing 26%-32% of the cell dry weight, were prepared from several strains of the yeasts Kloeckera apiculata, Debaryomyces hansenii, Zygosaccharomyces bailii, Kluyveromyces marxianus and Saccharomyces cerevisiae. Extraction of the walls with potassium hydroxide at 4 degrees C, followed by saturation of the alkali-soluble extract with ammonium sulphate gave fractions of mannoprotein, alkali-soluble glucan and alkali-insoluble glucan. Chitin was associated with the alkali-insoluble glucan. The proportions of the different fractions within the walls varied with the species and strain. Mannoprotein comprised between 25% and 34% of the walls, the content of alkali-insoluble glucan ranged from 15% to 48%, and the content of alkali-soluble glucan ranged from 10% to 48%. There was significant variation in the physical appearance of the alkali-soluble glucans and the relative viscosity of suspensions of these glucans. The yeasts could represent novel sources of polysaccharides with industrial and medical applications.

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We investigated the effect of single and multidopants on the thermoelectrical properties of host ZnO films. Incorporation of the single dopant Ga in the ZnO films improved the conductivity and mobility but lowered the Seebeck coefficient. Dual Ga- and In-doped ZnO thin films show slightly decreased electrical conductivity but improved Seebeck coefficient. The variation of thermoelectric properties is discussed in terms of film crystallinity, which is subject to the dopants' radius. Small amounts of In dopants with a large radius may introduce localized regions in the host film, affecting the thermoelectric properties. Consequently, a 1.5 times increase in power factor, three times reduction in thermal conductivity, and 5-fold enhancement in the figure of merit ZT have been achieved at 110 °C. The results also indicate that the balanced control of both electron and lattice thermal conductivities through dopant selection are necessary to attain low total thermal conductivity.

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Molecularly imprinted polymer (MIP) based fluorescent sensors require suitable fluorescent moieties which respond to the binding event with significant fluorescence changes. Two novel polymerisable coumarins: 6-styrylcoumarin-4-carboxylic acid (SCC) and 6-vinylcoumarin-4-carboxylic acid (VCC) have been designed and synthesised. These functional monomers allow for the preparation of fluorescent sensors of chiral amines, an important class of pharmaceutical compounds. MIPs were prepared with SCC and VCC, using (-)-ephedrine as a template and ethylene glycol dimethacrylate as a cross-linker. In MeCN, the polymers exhibited a decrease of fluorescence in response to amines, with some selectivity for the template over its enantiomer (+)-ephedrine and other structural analogues. Interestingly the response of SCC to (-)-ephedrine in the MIP occurs in the opposite direction to the change when recognition occurs in solution. The control polymers (NIPs) exhibited a lesser response to (-)-ephedrine, and no resolving power, suggesting that imprinting has been successful and selective recognition sites exist in the MIPs. Recognition in aqueous buffers at different pHs has also been investigated.

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