The local Fe structure and corresponding ferromagnetism are different for various concentrations of Fe-doped ZnO (Zn 1−x Fe x O, x = 0-0.07) films, which are prepared on LiNbO 3 (104) substrates by reactive magnetron sputtering. X-ray photoelectron spectroscopy and x-ray absorption near-edge structure (XANES) reveal that, when x 0.04, Fe is in the 2+ state and is incorporated into the wurtzite lattice of ZnO, and as x increases further, a second phase Fe 3 O 4 is induced. Furthermore, full multiple-scattering substitution ab initio calculation of Fe K -edge XANES is used to confirm the local structure of Fe in films with different x. The single-phase Fe-doped ZnO films (x 0.04) exhibit ferromagnetism above room temperature and the mechanism of bound magnetic polarons (BMPs) is proposed to discuss the magnetic properties. The presence of the second phase is responsible for the strong ferromagnetism for higher Fe concentration.

Hydrazine hydrate was used as a novel reducing agent for the synthesis of water soluble and stable cadmium selenide (CdSe) quantum dots (QDs). The as-prepared CdSe quantum dots were investigated by X-ray powder diffraction, high-resolution transmission electron microscopy, photoluminescence, and UV-vis absorption spectroscopy analyses. The results show that the as-prepared CdSe QDs possess a cubic crystal structure and an average size of 2 nm. The effects of the pH of the original solution, thioglycollic acid (TGA)/Cd2+ molar ratio (nTGA/nCd2+), and the Cd/Se molar ratio on the luminescence properties of CdSe QDs were also systematically analysed.

Thioglycolic acid-capped CdTexS(1 − x) quantum dots (QDs) were synthesized through a one-step approach in an aqueous medium. The CdTexS(1 − x) QDs played the role of a color conversion center. The structural and luminescent properties of the obtained CdTexS(1 − x) QDs were investigated. The fabricated red light-emitting hybrid device with the CdTexS(1 − x) QDs as the phosphor and a blue InGaN chip as the excitation source showed a good luminance. The Commission Internationale de L’Eclairage coordinates of the light-emitting diode (LED) at (0.66, 0.29) demonstrated a red LED. Results showed that CdTexS(1 − x) QDs can be excited by blue or near-UV regions. This feature presents CdTexS(1 − x) QDs with an advantage over wavelength converters for LEDs.

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Sucrose isomerase (SI) from Erwinia rhapontici is an intramolecular isomerase that is normally used to synthesise isomaltulose from sucrose by a mechanism of intramolecular transglycosylation. In this study, it was found that SI could synthesise α-arbutin using hydroquinone and sucrose as substrates, via an intermolecular transglycosylation reaction. Five phenylalanine residues (F185, F186, F205, F297, and F321) in the catalytic pocket of SI were chosen for sitedirected mutagenesis. Mutants F185I, F321I, and F321W, whose hydrolytic activities were enhanced after the mutation, could synthesise α-arbutin through intermolecular transglycosylation with a more than two-fold increase in the molar transfer ratio compared with wild type SI. The F297A mutant showed a strong ability to synthesise a novel α-arbutin derivative and a four-fold increase in its specific activity for intermolecular transglycosylation over the wild type. Our findings may lead to a new way to synthesise novel glucoside products such as α-arbutin derivatives by simply manipulating the Phe residues in the catalytic pocket. From the structure superposition, our strategy of manipulating these Phe residues may be applicable to other similar transglycosylating enzymes.

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