The spectroscopic characterization of zinc metaphosphate glasses, singly and doubly doped with Ce3+ and Mn2+ ions, is performed through excitation and emission spectra and decay time measurements. The weak yellow emission of Mn2+ is significantly enhanced by means of an efficient energy transfer from Ce3+ to Mn2+ ions. The efficiency of the energy transfer has been estimated based on spectroscopic data, and turned out to be about 53%. From spectroscopic data it can also be inferred that the energy transfer is nonradiative in nature and it takes place between Ce3+ and Mn2+ clusters formed in the glass through a short-range interaction mechanism. This impurity clustering appears to be a relevant finding for the design of efficient conversion phosphors of ultraviolet to visible light.

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We report the synthesis of Bi nanoparticles (Bi NPs) using the M13 phage as scaffold. The p8 protein of the phage is functionalized with thiol groups of different lengths, and these thiolated regions act as nucleation centers for Bi(3+) ions. The size distribution, shape, and resilience to oxidation of the Bi NPs depend on the length of the thiol group used. The NPs are characterized by high resolution transmission electron microscopy, Raman, and IR spectroscopies, matrix assisted laser desorption/ionization, and optical absorption. These results show that the nanoparticles are crystalline and have a typical diameter of ∼3.0 nm. The method of preparation presented here is reproducible and implies "greener" conditions than those reported elsewhere. To the best of our knowledge, this is the first report of bismuth nanoparticles synthesized by a biomineralization method.

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