In this work, we report the multifunctional character of neodymium-doped LaF₃ core/shell nanoparticles. Because of the spectral overlap of the neodymium emission bands with the transparency windows of human tissues, these nanoparticles emerge as relevant subtissue optical probes. For neodymium contents optimizing the luminescence brightness of Nd³⁺:LaF₃ nanoparticles, subtissue penetration depths of several millimeters have been demonstrated. At the same time, it has been found that the infrared emission bands of Nd³⁺:LaF₃ nanoparticles show a remarkable thermal sensitivity, so that they can be advantageously used as luminescent nanothermometers for subtissue thermal sensing. This possibility has been demonstrated in this work: Nd³⁺:LaF₃ nanoparticles have been used to provide optical control over subtissue temperature in a single-beam plasmonic-mediated heating experiment. In this experiment, gold nanorods are used as nanoheaters while thermal reading is performed by the Nd³⁺:LaF₃ nanoparticles. The possibility of a real single-beam-controlled subtissue hyperthermia process is, therefore, pointed out.

Photoluminescent, near-stoichiometric colloidal CuInSe2 nanocrystals are synthesized in large batches and with good colloidal quality. An organometallic method is used with a moderate reaction temperature (≤200 °C) to produce CuInSe2 nanocrystals with size-tunable photoluminescence spectra ranging from ∼600 to ∼850 nm. Two-dimensional photoluminescence excitation–emission maps are reported for the CuInSe2 nanocrystals, highlighting the size-tunable excitonic features. Type I heterostructured CuInSe2/ZnS nanocrystals are prepared and purified. They are found to have absolute photoluminescence quantum yields up to ∼26%. The potential to use CuInSe2/ZnS core/shell nanocrystals as a potential low toxicity active layer in light-emitting diodes is demonstrated by fabricating electroluminescent devices.

The future perspective of fluorescence imaging for real in vivo application are based on novel efficient nanoparticles which is able to emit in the second biological window (1000-1400 nm). In this work, the potential application of Nd(3+) -doped LaF(3) (Nd(3+) :LaF(3) ) nanoparticles is reported for fluorescence bioimaging in both the first and second biological windows based on their three main emission channels of Nd(3+) ions: (4) F(3/2) →(4) I(9/2) , (4) F(3/2) →(4) I(11/2) and (4) F(3/2) →(4) I(13/2) that lead to emissions at around 910, 1050, and 1330 nm, respectively. By systematically comparing the relative emission intensities, penetration depths and subtissue optical dispersion of each transition we propose that optimum subtissue images based on Nd(3+) :LaF(3) nanoparticles are obtained by using the (4) F3/2 →(4) I11/2 (1050 nm) emission band (lying in the second biological window) instead of the traditionally used (4) F(3/2) →(4) I(9/2) (910 nm, in the first biological window). After determining the optimum emission channel, it is used to obtain both in vitro and in vivo images by the controlled incorporation of Nd(3+) :LaF(3) nanoparticles in cancer cells and mice. Nd(3+) :LaF(3)nanoparticles thus emerge as very promising fluorescent nanoprobes for bioimaging in the second biological window.

CaMoO4 single crystals doped with Dy3+ were grown from sodium molybdate flux. Their absorption and visible emission spectra and decay curves were measured at different temperatures from 10 to 298 K. The complete energy level scheme has been deduced from the low-temperature measurements. The Judd-Ofelt parametrization scheme has been applied to the analysis of the room temperature absorption spectra. The calculated radiative lifetime of the 4F9/2 state is 152±5 µs, and it is in reasonable agreement with the experimental data. The decay curves measured in the 10-170 K temperature range are not exponential and obey the Inokuti-Hirayama model for energy transfer for an electric quadrupole-quadrupole interaction in the absence of diffusion among the donors. All spectral features are strongly affected by an inhomogeneous broadening connected with the `disordered crystal' character of the title compound.

Sodium cholate aggregates are adaptable host systems. The effect of changing the ionic strength with the addition of NaCl on the properties for guest binding to sodium cholate aggregates was investigated by using pyrene, perylene and 1-ethylnaphthalene as guests. Fluorescence, anisotropy and laser flash photolysis studies provided information on the protection efficiency of the aggregate bound guest, and provided information on the dynamics and correlation times for the host-guest system. Different trends for the protection efficiency of the bound guests were observed when the NaCl concentration was raised depending on the charge of the aqueous solubilized quencher. The increase in ionic strength was also shown to lengthen the correlation time of the aggregate bound guest and led to faster dynamics for the host-guest complex. These results show that the properties of sodium cholate aggregates as a supramolecular host system are significantly altered with changes in the ionic strength of the medium.

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YAl3 (BO3)4 crystals doped with Dy3+ were grown from a potassium trimolybdate flux. Their absorption and visible emission spectra and decay curves were measured at temperatures ranging from 10 to 298 K. The complete energy level scheme has been deduced from the low temperature measurements and reproduced by theoretical calculations based on a parametric Hamiltonian including coulombic, spin–orbit and crystal-field terms. The Judd–Ofelt parametrization scheme has been applied to the analysis of the room temperature absorption spectra. The calculated radiative lifetime of the 4F 9/2 state is 344 μs; this value is reasonably consistent with the experimental data.