Europium Thenoyltrifluoroacetonate Research Articles

Evaluation of the morphology and chelating agent excess in the design of luminescent metalorganic framework of europium thenoyltrifluoroacetone

Metal-organic frameworks (MOFs) have been synthesized using several elements, including the rare-earth. Research on luminescent diketones as an efficient alternative for the generation of OLEDs has increased in recent years, however, the evaluation of parameters such as morphology or excess of the cheating agent is not completely studied. In this work, the synthesis of thenoyltrifluoroacetone (TTA) combined with europium at the different chelating agent and rare earth ratio is presented, founding a change in morphology directed related with optical performance, structural analysis was performed using x-ray diffraction (XRD), and was observed a monoclinic structure in Eu 15% and Eu 20% samples. Morphological analysis was done with scanning electron microscopy (SEM). The TTA5Eu sample presented an irregular morphology with nanometric particles embedded, the TTA15Eu had a morphology of agglomerated particles, and TTA20Eu sample the morphology changes radically to an angular morphology. Nanowires were present in the sample of 25% Eu3+. The chemical properties were determined using Fourier transform infrared spectroscopy (FTIR), and the optical properties were measured by photoluminescence (FL). The results showed vibration bands and stretching of the thiophene group, without apparent change due to the chelation of the Eu3+.

Luminescent sensor based on the lanthanide-fibroin composite

Abstract This work aims to produce luminescent sensors based on lanthanide ions and silk fibroin composite films. Associating the physicochemical properties of fibroin with the spectroscopic properties of lanthanide ions can be a strategy to develop a new generation of biocompatible and biodegradable sensors with high transparency in the visible region. The results presented herein are a natural consequence of a previous study that used europium ions as structural probes in the composite fibroin matrix and investigated their potential application as photonic devices. Here, highly transparent thin films containing the silk fibroin matrix and an Eu3+ complex were produced by dip-coating under controlled conditions. Europium thenoyltrifluoroacetonate was employed as the luminescent component of the proposed sensor. The films were characterized by electronic spectroscopy in the UV–Vis region and photoluminescence. The effect of complex insertion on the refraction index of the silk fibroin film was studied. The results showed a high-intensity emission that is characteristic of europium β-diketone chelates, and the intensity of the 5D0 → 7F2 transition depended on the ammonia vapor concentration. To understand the whole process, different composite films were prepared, and the results corroborated the potential use of this system as a photonic sensor of vapors.

Single-cell temperature mapping with fluorescent thermometer nanosheets.

Recent studies using intracellular thermometers have shown that the temperature inside cultured single cells varies heterogeneously on the order of 1°C. However, the reliability of intracellular thermometry has been challenged both experimentally and theoretically because it is, in principle, exceedingly difficult to exclude the effects of nonthermal factors on the thermometers. To accurately measure cellular temperatures from outside of cells, we developed novel thermometry with fluorescent thermometer nanosheets, allowing for noninvasive global temperature mapping of cultured single cells. Various types of cells, i.e., HeLa/HEK293 cells, brown adipocytes, cardiomyocytes, and neurons, were cultured on nanosheets containing the temperature-sensitive fluorescent dye europium (III) thenoyltrifluoroacetonate trihydrate. First, we found that the difference in temperature on the nanosheet between nonexcitable HeLa/HEK293 cells and the culture medium was less than 0.2°C. The expression of mutated type 1 ryanodine receptors (R164C or Y523S) in HEK293 cells that cause Ca2+ leak from the endoplasmic reticulum did not change the cellular temperature greater than 0.1°C. Yet intracellular thermometry detected an increase in temperature of greater than ∼2°C at the endoplasmic reticulum in HeLa cells upon ionomycin-induced intracellular Ca2+ burst; global cellular temperature remained nearly constant within ±0.2°C. When rat neonatal cardiomyocytes or brown adipocytes were stimulated by a mitochondrial uncoupling reagent, the temperature was nearly unchanged within ±0.1°C. In cardiomyocytes, the temperature was stable within ±0.01°C during contractions when electrically stimulated at 2 Hz. Similarly, when rat hippocampal neurons were electrically stimulated at 0.25 Hz, the temperature was stable within ±0.03°C. The present findings with nonexcitable and excitable cells demonstrate that heat produced upon activation in single cells does not uniformly increase cellular temperature on a global basis, but merely forms a local temperature gradient on the order of ∼1°C just proximal to a heat source, such as the endoplasmic/sarcoplasmic reticulum ATPase.

Microscopic heat pulses activate cardiac thin filaments.

During the excitation-contraction coupling of the heart, sarcomeres are activated via thin filament structural changes (i.e., from the "off" state to the "on" state) in response to a release of Ca2+ from the sarcoplasmic reticulum. This process involves chemical reactions that are highly dependent on ambient temperature; for example, catalytic activity of the actomyosin ATPase rises with increasing temperature. Here, we investigate the effects of rapid heating by focused infrared (IR) laser irradiation on the sliding of thin filaments reconstituted with human α-tropomyosin and bovine ventricular troponin in an in vitro motility assay. We perform high-precision analyses measuring temperature by the fluorescence intensity of rhodamine-phalloidin-labeled F-actin coupled with a fluorescent thermosensor sheet containing the temperature-sensitive dye Europium (III) thenoyltrifluoroacetonate trihydrate. This approach enables a shift in temperature from 25°C to ∼46°C within 0.2 s. We find that in the absence of Ca2+ and presence of ATP, IR laser irradiation elicits sliding movements of reconstituted thin filaments with a sliding velocity that increases as a function of temperature. The heating-induced acceleration of thin filament sliding likewise occurs in the presence of Ca2+ and ATP; however, the temperature dependence is more than twofold less pronounced. These findings could indicate that in the mammalian heart, the on-off equilibrium of the cardiac thin filament state is partially shifted toward the on state in diastole at physiological body temperature, enabling rapid and efficient myocardial dynamics in systole.

Protein Corona Formation on Magnetic Nanoparticles Conjugated with Luminescent Europium Complexes

AbstractThe evaluation of the nanoparticles interactions with blood plasma enables a first and important insight on the organization of the adsorbed protein layer. In this context, we studied the formation of protein corona on magneto‐luminescent Fe3O4@calix‐Eu(TTA) nanoparticles in human plasma. The difference in the surface chemistry of F3O4 functionalized with calixarene (+30 mV ζ‐potential) and europium (III) thenoyltrifluoroacetonate (Eu3+‐TTA) complex (+7.4 mV ζ‐potential) affected the colloidal stability and hard corona composition of the nanoparticles, which were monitored by SDS‐PAGE gel electrophoresis, differential centrifugal sedimentation analyses and luminescence spectroscopy. Strikingly, after conjugation with Eu3+ TTA complex, the magnetic nanoparticles show lower adsorption affinity to proteins at higher blood plasma concentration. Moreover, the Eu3+ compound is featured with the narrow emission lines of 5D0→7FJ (J=0–4) transitions, imparting additional characteristics to bifunctional nanoparticles that were used as probes to evaluate the protein corona formation.

Spectral properties of hybrid associates of colloidal quantum dots Zn0.5Cd0.5S, europium tenoyltrifluoroacetonate and methylene blue

Hybrid associates formed from colloidal Zn0.5Cd0.5S quantum dots, passivated with thioglycolic acid, europium tenoyltrioteracetonate and methylene blue molecules, absorption, luminescence, IR and time-resolved spectroscopy technique are studied. The shift of the IR absorption bands of COO- and C=O groups of thioglycolic acid and europium thenoyltrifluoroacetonate has been detected. An increase in the efficiency of excitation of europium luminescence and a simultaneous increase lifetime of its luminescence upon adsorption on Zn0.5Cd0.5S quantum dots were found. Addition of methylene blue (thionine) molecules leads to quenching of the trap state luminescence of Zn0.5Cd0.5S and intracentric luminescence of Eu3+. A conclusion about the adsorption of Eu3+ on the surface of Zn0.5Cd0.5S quantum dots and the nonradiative energy transfer to methylene blue molecules was made.

High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient optical micro-imaging technique which can be used to map and quantify such behavior. Europium thenoyltrifluoroacetonate (EuTFC) has a 612 nm luminescence line whose activation efficiency drops strongly with increasing temperature, due to T-dependent interactions between the Eu3+ ion and the organic chelating compound. This material may be readily coated on to a sample surface by thermal sublimation in vacuum. When the coating is excited with ultraviolet light (337 nm) an optical micro-image of the 612 nm luminescent response can be converted directly into a map of the sample surface temperature. This technique offers spatial resolution limited only by the microscope optics (about 1 micron) and time resolution limited by the speed of the camera employed. It offers the additional advantages of only requiring comparatively simple and non-specialized equipment, and giving a quantitative probe of sample temperature.

Luminescent two-color tracer particles for simultaneous velocity and temperature measurements in microfluidics

The simultaneous and non-intrusive measurement of temperature and velocity fields in flows is of great scientific and technological interest. To sample the velocity and temperature, tracer particle based approaches have been developed, where the velocity is measured using PIV or PTV and the temperature is obtained from the intensity (LIF, thermographic phosphors) or frequency (TLC) of the light emitted or reflected by the tracer particles. In this article, a measurement technique is introduced, that relates the luminescent intensity ratio of individual dual-color luminescent tracer particles to temperature. Different processing algorithms are tested on synthetic particle images and compared with respect to their accuracy in estimating the intensity ratio. Furthermore, polymer particles which are doped with the temperature sensitive dye europium (III) thenoyltrifluoroacetonate (EuTTA) and the nearly temperature insensitive reference dye perylene are characterized as valid tracers. The results show a reduction of the temperature measurement uncertainty of almost 40% (95% confidence interval) compared to previously reported luminescent particle based measurement techniques for microfluidics.

Photo-reactive charge trapping memory based on lanthanide complex.

Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped. The luminescent complex emits intense red emission upon ultraviolet (UV) light excitation and serves as a trapping element of holes injected from the pentacene semiconductor layer. Memory window can be significantly enlarged by light-assisted programming and erasing procedures, during which the photo-induced excitons in the semiconductor layer are separated by voltage bias. The enhancement of memory window is attributed to the increasing number of photo-induced excitons by the UV light. The charges are stored in this luminescent complex for at least 104 s after withdrawing voltage bias. The present study on photo-assisted novel memory may motivate the research on a new type of light tunable charge trapping photo-reactive memory devices.

Effect of polymer matrix on temperature sensitivity of temperature sensitive paints

The thermal quenching behaviors of the temperature sensitivity paints (TSP) composed of europium(III) thenoyltrifluoroacetonate (EuTTA) and Eu-phenanthrene complex (Eu-2) in polystyrene (PS), polymethylmethacrylate (PMMA) and epoxy resin (EP) were investigated. It is found that both the emission intensity and temperature sensitivity were not only affected by the luminescence probes, but also by the polymer matrix. The interaction between probes and matrix results in the alteration of both the non-radiation decay rate and the activation energy of the non-radiative process for the thermal quenching process, i.e. larger activation energy of the non-radiative process shows higher temperature sensitivity and less emission intensity. Therefore, it was confirmed that the temperature sensitivity and luminescent intensity of TSP depended not only on the luminescence probes but also on the polymer matrix.

A Nanoparticle-Based Ratiometric and Self-Calibrated Fluorescent Thermometer for Single Living Cells

The homeostasis of body temperature and energy balance is one of the major principles in biology. Nanoscale thermometry of aqueous solutions is a challenging but crucial technique to understand the molecular basis of this essential process. Here, we developed a ratiometric nanothermometer (RNT) for intracellular temperature measurement in real time. Both the thermosensitive fluorophore, β-diketonate chelate europium(III) thenoyltrifluoroacetonate, and the thermoinsensitive fluorophore, rhodamine 101, which was used as a self-reference, are embedded in a polymeric particle that protects the fluorophores from intracellular conditions. The ratiometric measurement of single RNT spots is independent of the displacement of the RNT along the z-axis. The temperature is therefore determined at the location of each RNT under an optical microscope regardless of the dynamic movement of living cells. As a demonstration of the spot-by-spot intracellular thermometry, we successfully followed the temperature change in individual RNT spots in a single cell together with the Ca(2+) burst induced by the Ca(2+) ionophore ionomycin. The temperature increases differently among different spots, implying heterogeneous heat production in the cell. We then show that, in some spots, the temperature gradually decreases, while in others it remains high. The average temperature elevation within a cell is positively correlated to the increase in Ca(2+), suggesting that the activity and/or number of heat sources are dependent on the Ca(2+) concentration.

Patternable Temperature Sensitive Paint using Eu(TTA)3 for the Micro Thermal Imaging

This paper reports a novel patternable temperature sensitive paint (PTSP) which can be photolithographically patterned. The proposed PTSP consists of europium (III) thenoyltrifluoroacetone (Eu(TTA)3) as a luminescent material and SU-8 as a photosensitive matrix. The optimal patterning condition was investigated and the PTSP microstructures as small as 2 μm were successfully patterned. The luminescence from the micro-patterned PTSP was observed and the temperature sensitivity was measured as high as −0.8%/°C.

High spatial, temporal and temperature resolution thermal imaging method using Eu(TTA)3 temperature sensitive paint

This paper reports on a novel non-contact thermal imaging method with high spatial, temporal and temperature resolution for microdevice evaluation. This method uses a temperature sensitive paint with europium (III) thenoyltrifluoroacetone (Eu(TTA)3). The luminescence of Eu(TTA)3 was excited by a short pulsed UV light; a temporal resolution as high as 0.2 ms was achieved under normal CCD camera observation. Also, a spatial resolution of about 39 µm and a temperature fluctuation of about ±0.2 °C were demonstrated.

Synthesis and photophysical properties of new carbon-chain copolymers with europium-containing and carbazole fragments in pendant chains

Functionalized polynorbornenes with terpyridine and carbazole groups in pendant chains were prepared by metathesis copolymerization. The polymeric products prepared react with europium thenoyltrifluoroacetonate to form new carbon-chain copolymers with different ratios of organic and europium-containing units. The polymeric materials prepared were characterized by IR and NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and elemental analysis. All the europium-containing copolymers exhibit strong metal-centered photoluminescence in solution and in thin film.

Bidimensional fluorescence analysis and thermal design of europium thenoyltrifluoroacetonate based thermal-to-visible converter

We perform a bidimensional analysis to evaluate the variation of the fluorescence decay of europium thenoyltrifluoroacetonate (EuTTA) with temperature changes. We analyze how a specific thermal distribution modifies the spatial temperature of the sensing film and we study the corresponding fluorescence response using an integral functional of the emission decay. We present experimental results of a thermal distribution registered with the EuTTA-based thermal-to-visible conversion method. Furthermore, we analyze the spatial and temporal response of the proposed sensing element by using heat-transfer theory. Based on the presented analysis, we establish the optimal thermal and physical design for the sensing element of the proposed thermal-to-visible converter.

Conversion of absorbed thermal radiation into visible using europium thenoyltrifluoroacetonate

We evaluate the sensitivity and thermal resolution of the fluorescence of europium (III) thenoyltrifluoroacetonate (EuTTA) in order to convert absorbed thermal radiation into visible. We analyze the variation of the fluorescence properties of EuTTA (specifically, amplitude power and lifetime) after absorbed thermal radiation has caused a change in the local temperature of the material. We propose to analyze the thermal dependence of the fluorescence decay with an integral functional. Such operation correlates the variations of lifetime and amplitude in a single value. With this method of analysis, we study one parameter with increased thermal resolution and linear temperature dependence. The thermal resolution achieved with amplitude power is 0.11 K and with lifetime is 0.83 K at 305 K. The sensitivity of the integral functional is 25 nJ/K, yielding an increased thermal resolution of 0.07 K.

Preparation, Characterization, and Spectroscopic Properties of PC/PMMA Doped Blends: Study of the Effect of Rare-Earth Doping on Luminescence, Quenching Rate, and Lifetime Enhancement

Optical properties of highly transparent blends formed by bisphenol A polycarbonate (PC) and poly(methyl methacrylate) (PMMA) and doped with either europium(III) thenoyltrifluoroacetone hydrate [Eu(TTA)(3)-hydrate] or terbium(III) acetylacetonate hydrate [Tb(ACAC)(3)-hydrate] were studied. From the absorption/emission spectra (200 to 800 nm), percolation limits of less than 0.4 wt/wt% for Eu and above 0.7 wt/wt% for Tb were found. Lifetimes for 20/80 and 60/40 Tb-doped blends were from 1.0 to 1.5 ms, respectively, about 5 times longer than for a similar blend prepared with Langmuir-Blodgett film. For blends doped with Eu, the lifetimes were from 0.4 to 0.8 ms, almost double that for the pure complex. The results indicated interactions between the PC/PMMA blends and the rare-earth ion complex. Particularly, photoluminescent spectra evidenced the incorporation of the Eu(3+) and Tb(3+) ions into the blend, with quenching observed near 1.0 wt/wt%, except for the 20/80 blend doped with Eu ion, in which luminescence increased to 5 wt/wt %.

Fabrication of a Bi-luminophore Temperature Sensitive Coating by Embedding Europium Thenoyltrifluoroacetonate (EuTTA) and Perylene in Polystyrene

A new bi-luminophore system for optical sensing of temperature is described. The coating was fabricated by embedding europium thenoyltrifluoroacetonate (EuTTA) and perylene in polystyrene (PS) matrix. The luminescence emission of EuTTA was sensitive to temperature whereas perylene emission was temperature-insensitive and was used as a reference. Both luminophores were excited in the UV region of about 330 to 380 nm. The fluorescence emission of perylene and EuTTA occured at 474 nm and 615 nm respectively. The temperature sensitivities of both luminophores were influenced by (i) the type of polymer, and (ii) the concentration of luminophore in the matrix. Combining EuTTA and perylene in polystyrene matrix, a new bi-luminophore temperature sensing coating was developed. The temperature sensitivity of this coating was -1.80%/ degrees C in the temperature range of 5 degrees C to 50 degrees C. The emission characteristics of this temperature sensitive coating displayed a fully reversible response to temperature.

Temperature dependence of the luminescence lifetime of a europium complex immobilized in different polymer matrices

The temperature dependence of the luminescence lifetime of temperature sensor films based on europium (III) thenoyltrifluoroacetonate (EuTTA) as sensor dye in various polymer matrices such as polystyrene (PS), polymethylmethacrylate (PMMA), polyurethane (PU) and model airplane dope was studied and compared. The luminescence lifetime of EuTTA was found to depend on the polymer matrix. The temperature sensitivity of lifetime was maximum for EuTTA–PS coating in the temperature range of 10–60 °C. The effect of concentration of the sensor dye in the polymer on the lifetime and temperature sensitivity was also studied.

Quantitative evaluation of europium in blue ballpoint pen inks/offset printing inks tagged with europium thenoyltrifluoroacetonate by spectrofluorometry and ICP-AES

Tagging of writing/printing inks with suitable inorganic taggants such as rare-earth chelates has the potential to help document examiners identify fraud in sensitive written/printed documents. Selection of rare-earth chelates as taggants primarily depends on the satisfactory sensitivity of analytical determination and the absence of the taggants in normal varieties of inks used for document writing/printing. Spectrofluorometric determination of trace amounts of europium in blue ballpoint pen inks and offset printing inks tagged with europium thenoyltrifluoroacetonate was carried out with sodium tungstate solution. Sodium tungstate acts as a specific reagent that enhances the fluorescence intensity of the Eu3+ ion. The excitation and emission wavelengths are 270 nm and 605 nm respectively. The results were compared with the data obtained with ICP-AES. Satisfactory recoveries were observed with precision better than 5% RSD and comparable accuracy. Under the optimized experimental conditions, detection limits and quantitation limits were determined. The detection limits obtained by spectrofluorometry and ICP-AES were 0.01 microg/mL and 0.006 microg/mL respectively whereas the limits of quantitation were about 0.03 microg/mL and 0.018 microg/mL respectively. The spectrofluorometric method is rapid, selective, sensitive and accurate for the determination of europium in blue ballpoint pen ink and offset printing inks and may be suitable for application in the examination of sensitive documents to aid in document related crime investigation. The advantages and limitations of the tagging approach and proposed analytical techniques are discussed.