The determination of temperature is essential in many applications in the biomedical, technological, and industrial fields. Optical thermometry appears to be an excellent alternative for conventional electric temperature sensors because it is a non-contact method that offers a fast response, electromagnetic passivity, and high temperature sensitivity. In this paper, we propose an optical thermometer probe comprising an Er3+/Yb3+ co-doped tellurite glass attached to the tip of an optical fibre and optically coupled to a laser source and a portable USB spectrometer. The ratio of the up-conversion green emission integrated peak areas when excited at 980 nm was temperature dependent, and it was used to calibrate the thermometer. The thermometer was operated in the range of 5–50 °C and 50–200 °C, and it revealed excellent linearity (r2 > 0.99), suitable accuracy, and precisions of ±0.5 and ±1.1 °C, respectively. By optimizing Er3+ concentration, we could obtain the high green emission intensity, and in turn, high thermal sensitivity for the probe. The probe fabricated in the study exhibited suitable properties for its application as a temperature sensor and superior performance compared to other Er3+ -based optical thermometers in terms of thermal sensitivity.

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Encapsulation of ICG and IR-1061 in PCL–PEG micelles producing agents with increased stability of ICG and tunable PTT and PDT activity. The micelles are also useful for NIR imaging and NIR nanothermometry.

Tetranuclear silsesquioxane cages with tunable thermosensitive Tb3+-to-Eu3+ energy transfer were used for temperature sensing based on the Tb3+-to-Eu3+ emission intensity ratio (LIR) with excellent linearity and sensitivity.

We report here the synthesis, structure, luminescence, and magnetic properties of three new cage‐like tetranuclear silsesquioxanes (Et4N)2[(PhSiO1..5)8(Y0.75Dy0.25O1.5)4(O)(NO2.5)6(EtOH)2(MeCN)2] and (Cat)2[(PhSiO1.5)8(DyO1.5)4(O)(NO2.5)6(EtOH)2(MeCN)2] (Cat=Et4N or Ph4P). They present a characteristic green‐yellow emission. The Y3+/Dy3+ compound displays in addition a field‐induced Single Molecule Magnet (SMM) behavior making it the first reported bifunctional magneto‐luminescent silsesquioxane.

A multifunctional nanosystem was synthesized to be used as a dual sensor of UV light and temperature. NaGdF 4 :Yb 3+ :Er 3+ upconverting nanoparticles (UCNPs) were synthesized and coated with a silica shell to which a europium(III) complex was incorporated. The synthesis of NaGdF 4 UCNPs was performed via thermal decomposition of lanthanide ion fluoride precursors in the presence of oleic acid. To achieve sufficient water dispersibility, the surface of the hydrophobic oleate-capped UCNPs in the hexagonal phase was modified by a silica coating through a modified Stöber process through a reverse microemulsion method. An Eu(tta) 3 (tta: thenoyltrifluoroacetonate) complex was prepared in situ at the silica shell. A dual-mode nanothermometer was obtained from a near infrared to visible upconversion fluorescence signal of Er 3+ ions together with UV-excited downshifting emission from the Eu 3+ complex. Measurements were recorded near the physiological temperature range (293–323 K), revealing excellent linearity ( R 2 > 0.99) and relatively high thermal sensitivities (≥1.5%·K –1 ). The Eu(tta) 3 complex present in the silica shell was tested as the UV sensor because of the Eu 3+ luminescence dependence on UV-light exposure time.

a b s t r a c tNanostructured films prepared by Layer-by-Layer technique and containing silk fibroin, antigenic peptide NS5A-1 derived from hepatitis C virus (HCV) NS5A protein and YVO 4 :Eu 3 þ luminescent nanoparticles, were utilized in sensing of hepatitis C. Detection system exploits the biorecognition between the antibody anti-HCV and the antigenic peptide NS5A-1 through changes in luminescence properties. Films deposition was monitored by UV-vis Absorption and Fluorescence Spectroscopy measurements at each bilayer deposited. The Eu 3 þ luminescence properties were evaluated in the presence of anti-HCV for optical detection of specific antibody and anti-HIV used as negative control. Significant changes in luminescence were observed in the presence of anti-HCV concentrations. A new immunosensor platform is proposed for optical detection of hepatitis C.& 2015 Elsevier B.V. All rights reserved. Recently, our group reported an electrochemical immunosensor for HCV that explores biorecognition between an antigenic peptide (PPLLESWKDPDYVPPWHG) derived from the HCV NS5A-1 protein and anti-HCV [19], where the peptide was immobilized into Layerby-Layer (LbL) films, alternated with silk fibroin (SF). Using cyclic voltammetry, it was possible to detect the anti-HCV antibody for concentrations between 0.01 and 0.2 μg mL À 1 .

The role of orange based pectin in the nucleation and growth of silver and gold nanoparticles is addressed. Pectin is a complex polysaccharide found in fruits such as oranges, lemons, passion fruits or apples. It displays smooth and hairy chain regions containing hydroxyl-, ester-, carboxylate-and eventually amine groups that can act as surface ligands interacting under various pH conditions more or less efficiently with growing nanometals. Here, a high methoxy pectin (> 50% esterified) was used as a stabilizer/reducing agent in the preparation of gold, silver and silver-gold nanoparticles. Commercial pectin (CP) and pectin extracted from orange bagasse (OP) were used. Optionally, trisodium citrate or oxalic acid we used to reduce AgNO 3 and HAuCl 4 in aqueous environment. Characterization methods included UV-VIS absorption spectroscopy, transmission electron microscopy, electron diffraction and energy-dispersive x-ray spectroscopy. The results show that under different pH conditions, pectin and reducing agents allow producing various nanostructures shapes (triangles, spheres, rods, octahedrons and decahedrons) often with high polydispersity and sizes ranging between 5 nm and 30 nm. In addition, depending on Ag/Au-ratio and pH, the surface plasmon bands can be continuously shifted between 410 nm and 600 nm. Finally, pectin seems to be a highly efficient stabilizer of the colloidal systems that show a remarkable stability and unchanged optical spectral response even after five years.