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Well dispersed non-stabilized lanthanum oxyfluoride and fluoride nanoparticles were prepared in situ in thin silica films from rapid thermal decomposition of lanthanum tris-trifluoroacetate under nitrogen atmosphere. The thin silica films were obtained from sol-gel method and spin-coating. The spectroscopic properties of the non-stabilized nanoparticles as well the nanoparticles dispersed into thin silica films were studied in order to apply the system in future photonic applications such as erbium(III)-doped waveguide amplifiers. The non-stabilized nanoparticles were characterized by XRD, FT-IR, Transmission Electron Microscopy, Confocal Raman Spectroscopy and steady-state and timeresolved Luminescence Spectroscopy and these characterizations were used as a starting point to characterize the nanoparticles dispersed into the films. According to the temperature of the thermal treatments, the non-stabilized nanoparticles may present Eu(III)-doped LaOF in tetragonal and rhombohedral phases as well as a mixed phase of Eu(III)-doped LaF 3 and LaOF. The tetragonal LaOF phase has C 4v La(III) point symmetry and is more symmetric than the rhombohedral LaOF phase, where the La(III) ion has C 3v symmetry, consequently tetragonal LaOF presented lower U 2 values than rhombohedral LaOF. Theoretical calculations of Judd-Ofelt intensity parameters were also performed and were in good agreement with the experimental values. The samples containing the mixed phase of LaF 3 and LaOF presented lower values of intensity parameters than pure LaOF phases. The samples containing the mixed phase presented higher values of emission lifetimes and quantum efficiencies. Confocal Raman spectroscopy of these samples complements the luminescence studies and indicates which LaOF phase is present in the mixed phase of LaF 3 and LaOF. The rapid thermal decomposition of the precursor tris-trifluoroacetate on thin silica films results in well-dispersed 10 nm nanoparticles. The mixed phase of LaF 3 and LaOF phases is also present in thin films. The luminescence of the Eu(III) and Er(III)/Yb(III)-doped LaF 3 /LaOF nanoparticles containing thin silica films presented broad emission bands suggesting that in the future the systems may be applied as erbium(III)-doped waveguide amplifiers.

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Biological applications of phosphorescent probes for sensing molecular oxygen (O2) and bioimaging have gained popularity, but their choice is rather limited. We describe a family of new heterosubstituted phosphorescent bioprobes based on the Pt(II)-tetrakis(pentafluorophenyl)porphyrin (PtPFPP) dye. The probes are produced by simple click modification of its para-fluorine atoms with thiols, such as 1/2-thio-glucose, thio-poly(ethylene glycol) (PEG), or cysteamine. The probes were designed to have one cell-targeting moiety and three polar moieties forming a hydrophilic shell. Their chemical synthesis and purification were optimized to produce high reaction yields and easy scale-up. The ability to perform as cell-permeable or -impermeable probes was tuned by the polarity and molecular charge of the bioconjugate. The new PtPFPP derivatives were characterized for their spectral properties and cell-penetrating ability in the experiments with mammalian cell cultures, using a time-resolved fluorescence reader and PLIM imaging detection. Structure–activity relationships were established. Thus, the tri- and tetra-PEGylated structures showed low cell internalization allowing their use as extracellular probes, while cysteamine derivatives performed as efficient intracellular probes. No significant cytotoxicity was observed for all of the probes under the experimental conditions used.

New luminescent temperature probes were synthesized based on the dispersion of the europium(III) [Eu(tta)3(H2O)2] complex (tta=thenoyltrifluoroacetonate), and the covalent bond of europium(III) [Eu(tta)3(adppo)(H2O)] and [Eu(tta)3(adppo)2] (adppo=allyldiphenylphosphine oxide) complexes by the hydroslylilation reaction between the allyl group and the hydride terminal polydimethylsiloxane (PDMS). Phosphine oxide coordination to the europium(III) ion increases the lifetime values and changes the emission profile to a more symmetrical europium(III) chemical environment. The membranes shows a decrease in lifetime values with the increase of temperature, and the dynamic range of the luminescent membranes shifts to higher temperatures by successive substitution of water molecules for the phosphine oxide ligand. Sensitivities of 6.76, 7.80 and 8.35 μS C−1 were obtained for the membranes containing the [Eu(tta)3(H2O)2], [Eu(tta)3(adppo)(H2O)] and [Eu(tta)3(adppo)2] complexes, respectively. Low oxygen cross sensitivity are observable in the membranes containing the coordinated adppo molecule, allowing their use in multiparametric sensors.