Spectroscopic Characteristics Research Articles

Near-infrared and green light emission spectroscopic characteristics of Er3+ doped alumina–phosphate glasses

Near-infrared and green light emission spectroscopic characteristics of Er3+ doped alumina–phosphate glasses

Dynamic Imaging of Lipid Droplets in Cells and Tissues by Using Dioxaborine Barbiturate-Based Fluorogenic Probes.

Lipids are essential for various cellular functions, including energy storage, membrane flexibility, and signaling molecule production. Maintaining proper lipid levels is important to prevent health problems such as cancer, neurodegenerative disorders, cardiovascular diseases, obesity, and diabetes. Monitoring cellular lipid droplets (LDs) in real-time with high resolution can provide insights into LD-related pathways and diseases owing to the dynamic nature of LDs. Fluorescence-based imaging is widely used for tracking LDs in live cells and animal models. However, the current fluorophores have limitations such as poor photostability and high background staining. Herein, we developed a novel fluorogenic probe based on a push-pull interaction combined with aggregation-induced emission enhancement (AIEE) for dynamic imaging of LDs. Probe 1 exhibits favorable membrane permeability and spectroscopic characteristics, allowing specific imaging of cellular LDs and time-lapse imaging of LD accumulation. This probe can also be used to examine LDs in fruit fly tissues in various metabolic states, serving as a highly versatile and specific tool for dynamic LD imaging in cellular and tissue environments.

Evaluation of Density Functional Theory-Generated Data for Infrared Spectroscopy of Novel Psychoactive Substances Using Unsupervised Learning

Novel psychoactive substances (NPSs) are compounds plotted to modify the chemical structures of prohibited substances, offering alternatives for consumption and evading legislation. The prompt emergence of these substances presents challenges in health concerns and forensic assessment because of the lack of analytical standards. A viable alternative for establishing these standards involves leveraging in silico methods to acquire spectroscopic data. This study assesses the efficacy of utilizing infrared spectroscopy (IRS) data derived from density functional theory (DFT) for analyzing NPSs. Various functionals were employed to generate infrared spectra for five distinct NPS categories including the following: amphetamines, benzodiazepines, synthetic cannabinoids, cathinones, and fentanyls. PRISMA software was conceived to rationalize data management. Unsupervised learning techniques, including Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), and t-distributed stochastic neighbor embedding (t-SNE), were utilized to refine the assessment process. Our findings reveal no significant disparities among the different functionals used to generate infrared spectra data. Additionally, the application of unsupervised learning demonstrated adequate segregation of NPSs within their respective groups. In conclusion, integrating theoretical data and dimension reduction techniques proves to be a powerful strategy for evaluating the spectroscopic characteristics of NPSs. This underscores the potential of this combined methodology as a diagnostic tool for distinguishing IR spectra across various NPS groups, facilitating the evaluation of newly unknown compounds.

Optical-spectroscopic and isotope-geochemical characteristics of zircons from diamond-bearing placers in Yakutia as indicators of diamond ore bodies

Research subject. Zircon grains from diamond placers of the Molodo and Ebelyakh rivers of the Yakut Arctic. Aim. To study the indicator characteristics of zircon to determine sources of diamonds and ways of their transfer to placers; to analyze optical-spectroscopic and isotope-geochemical parameters of zircon grains, their microelemental, U-Pb, and Lu-Hf isotope composition. Materials and methods. A LA-ICP-MS analysis of the U-Pb isotopic and trace element composition of zircon was carried out using a NexION 300S mass spectrometer with an NWR 213 attachment. An analysis of the Lu-Hf isotope system was carried out using a Neptune Plus mass spectrometer with an NWR 213 attachment, located in a room of cleanliness class 7 ISO at the Geoanalitik Center for Collective Use (IGG Ural Branch of the Russian Academy of Sciences, Ekaterinburg). Raman spectra were obtained using a LabRAM HR800 Evolution confocal spectrometer. CL spectra were obtained using a Jeol JSM6390LV scanning electron microscope equipped with a Horiba H-CLUE iHR500 attachment. Results. The local optical spectroscopic characteristics (Raman spectra and catholuminescence) of zircon grains were established, which made it possible to substantiate the conclusion about their high crystallinity and homogeneity (monochrony), as well as to select international zircon standards with similar characteristics for use in LA-ICP-MS analysis to ensure similar conditions for evaporation of the substance and fractionation parameters of the U and Pb elements. LA-ICPMS data on the microimpurity, U-Pb and Lu-Hf isotopic composition of zircon grains from diamond placers, as well as the dose values of their self-irradiation, are presented. Conclusions. The obtained U-Pb dating contributes to reconstructing a more precise history, character, and sequence of manifestation of kimberlite magmatism, tectonic processes, and migration routes of kimberlite material and diamonds across the Siberian craton, within the Yakut kimberlite province.

Probing noncovalent binding, spectroscopic characteristics and antiproliferative behavior of inclusion complex between quinoline and para-sulfonatothiacalix[4]arene

The inclusion complex between bowl-shaped para-sulfonatothiacalix[4]arene (TSCX4) macrocycle and quinoline has been studied with a unison of UV–visible, infra-red, flourescence emission and 1H nuclear magnetic resonance (NMR) and 2D nuclear overhauser effect spectroscopy (NOESY), high resolution mass spectrometry (HRMS) experiments. Both 1H NMR titration and HRMS experiments point to 1:1 stoichiometry for the water soluble Q ⊂ TSCX4 complex. The electronic structure of the inclusion complex obtained from density functional theory (DFT) showed a partial encapsulation of quinoline guest, which is held within the host cavity by C–H---π, π---π and hydrogen bonding interactions. The fluorescence emission spectra upon complexation display marginal blue shift of the 411 nm band in TSCX4. Moreover, the binding constant (7.1 × 103 M−1) determined from fluoresence emission experiments underline the effective host–guest binding in the complex, which was corroborated through frequency up-shift (‘blue shift’) of characteristic Ar-OH (3433 cm−1) and SO3- vibrations (1141 cm−1 and 1037 cm−1) in the measured infrared spectra of TSCX4. The antiproliferative activitities of the Q ⊂ TSCX4 complex against HeLA, MDA-MB-231and N2a cells are presented. The Q ⊂ TSCX4 complex has been shown to be efficient against N2a (neuroblastoma) cell line.

Synergistic effect of WO3 on structural, physical, optical, and dielectric characteristics of multicomponent borate glasses for optoelectronic applications

This study demonstrates the promising potential of WO3-doped calcium lithium silicate borate glasses as a multifunctional material with adjustable characteristics for a range of current technological purposes. The melt quenching technique was used for the manufacture of calcium lithium silicate borate glass samples doped with WO3 with a chemical composition of (50-x)B2O3+10SiO2+15CaO+25Li2O + xWO3, where x = 0, 1, 2, 3, and 5 mol%. Raman spectroscopy and UV optical absorption methods were used to investigate the spectroscopic characteristics of glass samples. The dielectric characteristics of the produced glass samples were investigated by broadband dielectric spectroscopy (BDS) measurements. The extremely short-range ordering structural matrices revealed by X-ray diffraction have validated the amorphous nature. The Raman spectra of the calcium lithium silicate borate glass exhibit considerable differences from those of glasses containing WO3. The prepared glass samples exhibited an obvious relationship between the replacement of WO3 and their density and molar volume. As a result of a modification in the structure, the values of packing density (Vp) and oxygen packing density (OPD) decrease as the molar concentration of WO3 increases. The inclusion of WO3 increased the optical absorbance of the synthesized glasses, as demonstrated by UV–Vis optical absorption spectra. According to the dielectric characteristics, the dielectric loss and dielectric constant decrease with frequency, while the AC electrical conductivity exhibits a progressive increase.

Study of Octupole Transitions in Xe, Ba, Ce and Nd Nuclei within Interacting Boson Model

For nuclei with 54≤Z≤60 and 86≤N≤94, the results regarding the excitation spectra at low energies, both in positive and negative parity, as well as the transition probabilities for electric dipole (B(E1)), quadrupole (B(E2)), and octupole transitions (B(E(3)), indicate the emergence of significant octupole behavior. These observations have been made using the Interacting Boson Model-1 (IBM-1). The study examines the onset of octupole deformation and its impact on the spectroscopic characteristics in even-even neutron-rich lanthanide isotopes, specifically in the Ba and Nd nuclei. The investigation compares the results obtained from the Interacting Boson Model-1 (IBM-1) with the existing experimental data. The focus is on understanding how the addition of neutrons influences the development of octupole deformation and its manifestation in the observed spectroscopic features. The onset of strong octupolarity for Z≈ 56 and N ≈ 88 nuclei is indicated by the results obtained for the electric dipole, quadrupole, and octupole transition probabilities, as well as the low-energy positive and negative-parity excitation spectra. Conversely, discrepancies between the spectroscopic data and the IBM results suggest that the mapping quality needs to be evaluated in order to determine if the mapped boson Hamiltonian or the fermionic calculations are the source of the issues.

Molecular Design Using Selected Concentration Effects in Optically Activated Fluorescent Matrices.

Molecular physics plays a pivotal role in various fields, including medicine, pharmaceuticals, and broader industrial applications. This study aims to enhance the methods for producing specific optically active materials with distinct spectroscopic properties at the molecular level, which are crucial for these sectors, while prioritizing human safety in both production and application. Forensic science, a significant socio-economic field, often employs hazardous substances in analyzing friction ridges on porous surfaces, posing safety concerns. In response, we formulated novel, non-toxic procedures for examining paper evidence, particularly thermal papers. Our laboratory model utilizes a polyvinyl alcohol polymer as a rigid matrix to emulate the thermal paper's environment, enabling precise control over the spectroscopic characteristics of 1,8-diazafluoro-9-one (DFO). We identified and analyzed the cyclodimer 1,8-diazafluoren-9-one (DAK DFO), which is a non-toxic and biocompatible alternative for revealing forensic marks. The reagents used to preserve fingerprints were optimized for their effectiveness and stability. Using stationary absorption and emission spectroscopy, along with time-resolved emission studies, we verified the spectroscopic attributes of the new structures under deliberate aggregation conditions. Raman spectroscopy and quantum mechanical computations substantiated the cyclodimer's configuration. The investigation provides robust scientific endorsement for the novel compound and its structural diversity, influenced by the solvatochromic sensitivity of the DFO precursor. Our approach to monitoring aggregation processes signifies a substantial shift in synthetic research paradigms, leveraging simple chemistry to yield an innovative contribution to forensic science methodologies.

Sun-as-a-star Study of an X-class Solar Flare with Spectroscopic Observations of CHASE

Sun-as-a-star spectroscopic characteristics of solar flares can be used as a benchmark for the detection and analysis of stellar flares. Here, we study the Sun-as-a-star properties of an X1.0 solar flare, using high-resolution spectroscopic data obtained by the Chinese Hα Solar Explorer (CHASE). A noise reduction algorithm based on discrete Fourier transformation is first employed to enhance the signal-to-noise ratio of the space-integral Hα spectrum, with a focus on its typical characteristics. For the flare of interest, we find that the average Hα profile displays a strong emission at the line center and an obvious line broadening. It also presents a clear red asymmetry, corresponding to a redshift velocity of around 50 km s−1 that slightly decreases with time, consistent with previous results. Furthermore, we study how the size of the space-integral region affects the characteristics of the flare's Sun-as-a-star Hα profile. It is found that although the redshift velocity calculated from the Hα profile remains unchanged, the detectability of the characteristics weakens as the space-integral region becomes larger. An upper limit on the size of the target region where the red asymmetry is detectable is estimated. It is also found that the intensity in Hα profiles, measured by the equivalent widths of the spectra, are significantly underestimated if the Hα spectra are further averaged in the time domain.

Origin of Color and Spectral Characteristics of Nanhong Agate from Northeast Yunnan, China

Nanhong agate has attracted public attention as the most distinctive gemstone in China. Owing to the limited data on Nanhong agates from a new production area in northeastern Yunnan, this paper presents the first data from gemological studies on these agates. Complex investigations using Fourier-transform infrared (FTIR) spectrometry, ultraviolet–visible (UV–VIS) luminescence spectrometry, Raman spectroscopy, polarizing microscopy, scanning electron microscopy (SEM), electron microprobe (EPMA), and laser ablation–inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses were carried out to obtain basic data concerning the gemological properties, microstructure, and spectroscopic and geochemical characteristics of this interesting material. The results illustrate that Nanhong agates from northeastern Yunnan are mainly composed of α-quartz and also contain certain amounts of moganite, illite, goethite, and hematite. The typical red (yellow) and white appearance can be attributed to the microstructure of the agates, the contents of Fe and Al impurities, and trace elements. The Raman spectra, microstructure, and chemical composition of the unique “yellow-skinned” agates from northeastern Yunnan are significantly different from those of other types of Nanhong agate. This work lays a foundation for the future identification and research of this type of Nanhong agate.

DFT and TD-DFT study of substituent effects on structure, spectroscopic and photoelectric characteristics of D-A dyes for solar cells

To study the structure, photophysical and photoelectric properties of chlorophyll derivatives, the chlorophyll derivative dyes (CHL-1 and CHL-6) were investigated to exploit their utility in solar cells. The two experimental dye systems were simulated using DFT and TD-DFT, and optimization of the structure, absorption spectroscopy, chemical parameters, electron transfer, and dye regeneration processes were studied to analyze their different performance. Furthermore, a functional group substitution strategy was adopted to improve PCE, and the electron-withdrawing groups were introduced into the acceptor group of CHL-6 to design new chlorophyll derivative molecules, in which the high efficiency for designed molecule CN-1 is 1.19 times that of the experimental molecule CHL-6. This study provides insights into the optoelectronic properties of chlorophyll derivatives, and introducing specific electron-withdrawing groups in the acceptor fraction helps to improve photoelectric efficiency.

Hydrogen sulfide chemiresistive sensor based on swift heavy ion irradiated cerium-based metal–organic framework/graphene oxide composite

Herein, we report ultrahigh sensitive and selective hydrogen sulfide (H2S) chemiresistive sensor using SHI irradiated cerium-based metal–organic framework (MOF)/graphene oxide composite (Ce-BTC/GO). The solvothermal synthesized Ce-BTC/GO coated on an indium tin oxide (ITO) electrode, irradiated by the 100 MeV Au+ ion at the fluence rate 5 × 1010 ions/s, 5 × 1011 ions/s and 5 × 1012 ions/s has been tested for chemiresistive sensing of H2S. As irradiated, Ce-BTC/GO was multi-parametrically tested for XRD, FE-SEM, FTIR spectroscopy, Raman spectroscopy and I-V characteristics for its structural, morphological, spectroscopic and electrical characteristics. The result reveals that the irradiation treatment greatly affects the electric characteristics of the GO, achieving dramatic conductivity modulation in the presence of H2S gas, it also creates the surface sites for the H2S absorption and hence shows excellent real-time sensing performance below the maximum residue limit established by OSHA (Occupational Safety and Health Administration). SHI irradiated Ce-BTC/GO sensor also shows excellent response/recovery time, ultrahigh reproducibility, good repeatability and stability at room temperature. The sensor allows the detection of H2S with a sensitivity of 54.70% in a concentration range of 10–100 ppm with a limit of detection 10 ppm.

Multiple plateaus of high-sideband generation from Floquet matters

We theoretically report that high-order sideband generation (HSG) from Floquet matters driven by a strong terahertz light while engineered by weak infrared light can achieve multiple plateau HSG. The Floquet-engineering systems exhibit distinctive spectroscopic characteristics that go beyond the HSG processes in field-free band-structure systems. The spatial-temporal dynamics analyses under Floquet-Bloch and time-reversal-symmetry theories clarify the spectra and its odd-even characteristics in the HSG spectrum. Our work demonstrates the HSG of Floquet matters via Floquet engineering and indicates a promising way to extract Floquet material parameters in future experiments.

Seeing is believing: Correlating optoelectronic functionality with atomic scale imaging of single semiconductor nanocrystals.

A unique on-chip method for the direct correlation of optical properties, with atomic-scale chemical-structural characteristics for a single quantum dot (QD), is developed and utilized in various examples. This is based on performing single QD optical characterization on a modified glass substrate, followed by the extraction of the relevant region of interest by focused-ion-beam-scanning electron microscope processing into a lamella for high resolution scanning transmission electron microscopy (STEM) characterization with atomic scale resolution. The direct correlation of the optical response under an electric field with STEM analysis of the same particle allows addressing several single particle phenomena: first, the direct correlation of single QD photoluminescence (PL) polarization and its response to the external field with the QD crystal lattice alignment, so far inferred indirectly; second, the identification of unique yet rare few-QD assemblies, correlated directly with their special spectroscopic optical characteristics, serving as a guide for future designed assemblies; and third, the study on the effect of metal island growth on the PL behavior of hybrid semiconductor-metal nanoparticles, with relevance for their possible functionality in photocatalysis. This work, therefore, establishes the use of the direct on-chip optical-structural correlation method for numerous scenarios and timely questions in the field of QD research.

Influence of Dy3+ ions on spectroscopic studies of thermally stable telluro zinc phosphate glasses for white light emitting devices

A transparent series of telluro zinc phosphate glasses with varying Dy3+ ion concentrations (BTZPDy) were synthesized using a melt-quenching procedure. The non-crystalline/amorphous form of the BTZPDy glass matrices has been demonstrated via an X-ray diffraction (XRD) profile. As a way of recognizing the proficient usage of the obtained BTZPDy glass matrices in the white light emitting devices, the spectroscopic characteristics such as optical absorption, photoluminescence excitation (PLE) and emission, as well as temperature-dependent photoluminescence (TDPL) were conducted and investigated in detail. The absorption spectrum was determined in the n-UV to NIR range for the as-prepared BTZPDy1.0 glass sample and the optical energy band gap has been assessed via utilizing Tauc’s plot. In the visible range, photoluminescence spectra demonstrate three distinct emission peaks under different n-UV excitations, among which an intense emission peak around 575 nm is related to the 4F9/2 → 6H13/2 transition in the prepared BTZPDy glasses. The color coordinates (x, y) for the prepared BTZPDy1.0 glass were situated in the white light zone of the CIE graph and adjacent to the standard white light region (0.33, 0.33). Furthermore, TDPL spectral studies suggest the excellent thermal stability of BTZPDy glass samples alongside a high value of activation energy. In view of the above results, as-prepared BTZPDy glasses can be utilized for the fabrication of thermally stable white light emitting devices.

Synthesis and characterization of zinc doped nickel nanoferrites via sol-gel auto-combustion technique

Over the last few decades, numerous researchers have made significant contributions to the development of spinel ferrite owing to its unique and versatile structural, spectroscopic, and magnetic characteristics. These ferrites are extensively used in various applications such as microwaves, drug delivery, gas sensors, and electronic devices. Their technological applications require low porosity, high density, and specified microstructure. In this work, we prepared Zinc-doped Nickel nanoferrites Ni1-xZnxFe2O4 (x= 0, 0.1, 0.2, 0.3) using the sol-gel auto-combustion technique. Structural analysis of prepared samples was done using X-ray diffraction and Scanning Electron Microscopy, the elemental composition was examined using EDAX and optical studies using UV-visible spectroscopy. The average crystallite size was found in the 40.6 to 64.92 nm range. EDAX analysis confirmed the presence of expected elements in the samples. From UV-visible spectroscopy characterization studies it was observed that as particle size increases, there will be an increase in the band gap energy of ferrite nanoparticles. The Nickel-Zinc nanoferrite absorbs energy in the range of 233nm to 237nm.

Luminescence properties of CdF2 single crystals co-doped with Er3+ and Y3+ ions.

The luminescence properties of erbium and yttrium co-doped cadmium difluoride with three different concentrations of yttrium were investigated. First, we synthesized single crystal samples with good optical quality using the Bridgman technique. From the optical absorption spectra, recorded at room temperature, both in the ultraviolet-visible and infrared spectral ranges, Judd-Ofelt analysis was performed based on yttrium concentrations to predict the radiative properties of Er3+ luminescent ions. For the 10% optimum concentration of yttrium, a detailed photoluminescence investigation was carried out. We mainly explored green, red, and near-infrared fluorescence under different excitation wavelengths and presented their highlight spectroscopic characteristics. The desired transitions had relatively high emission cross-sections both under visible and near-infrared excitation. Optical gain followed a similar trend. Furthermore, the dynamic fluorescence study showed a significant increase in the measured lifetime under an 800 nm infrared excitation. The upconversion process under an 800 nm excitation produced quantum efficiency greater than 100% due to the contribution of more than one energy transfer mechanism.

Growth and spectroscopic properties of Ca3(Ta,Ga)5O12:Pr3+ single crystal as a promising new laser material in the visible domain

Structurally disordered Pr3+-doped Ca3(Ta,Ga)5O12 - Pr:CTGG single crystal was grown by the Czochralski technique for the first time and its spectroscopic properties were investigated. Modified Judd-Ofelt analysis was applied to determine spectroscopic and laser emission characteristics. Based on low-temperature absorption and emission spectra, the partial energy levels of Pr3+ ions have been obtained and a multicenter structure of the optical spectra was highlighted. The electron-phonon interactions were also observed in the emission spectra corresponding to the 3P0 → 3H4 transition under different excitation wavelengths. The fluorescence decays of the 3P0 and 1D2 levels were measured. The emission cross-sections corresponding to the 3P0 → 3H4 (486.5 nm) and 3P0 → 3F2 (652.7 nm) transitions were found to be σem = 19 × 10−20 cm2 and σem = 15 × 10−20 cm2, respectively. The values for other parameters that may predict the possibility of achieving efficient laser emission, especially at 486.5 nm, such as quantum efficiency (ⴄ = 50 %), gain bandwidth (σem× Δλeff, = 32.2 × 10−26 cm3), and optical gain (σem× τmeas = 12.86 × 10−25 cm2 s) were determined. The obtained results indicate that the Pr:CTGG crystal has a high potential for obtaining efficient laser emission in the blue domain.

Aza-Diphosphido-Bridged Di-Iron Complexes Related to the [FeFe]-Hydrogenases

The reaction of the dianionic species [Fe2(CO)6(μ-PPh)2]2− with tBuN(CH2Cl)2 gives the di-iron carbonyl aza-diphosphido-bridged complex [Fe2(CO)6(µ-{P(Ph)CH2}2NtBu)] (1). Attempts to prepare 1 by click-chemistry by reacting [Fe2(CO)6(μ-PHPh)2] with CH2O and tBuNH2 afforded a bis-phosphido compound [Fe2(CO)6(µ-P(Ph)CH2NHtBu)2] (2) which exists as two, syn and anti, isolable isomers depending on the relative orientation of the groups carried by the phosphorus atoms. In the presence of HBF4.Et2O, in dichloromethane, 1 leads to the stabilized ammonium species [Fe2(CO)6(µ-{P(Ph)CH2}2NHtBu)](BF4) (3). The derivatives 1–3 were characterized by IR and 1H, 31P-{1H} NMR spectroscopies. Their structures in a solid state were determined by X-ray diffraction analyses, which accord with their spectroscopic characteristics.

Synthesis and Optical Properties of Erbium-Doped Sodium Silicate in Sol-Gel Matrix

AbstractIn this study, we investigated how the concentration of erbium (0.0, 1, 2 mol% Er) affects the structural and optical properties of thin films made from sol-gel sodium silicate doped with erbium nitrate, thermally treated at 250 °C. Through systematic investigation, we explore the structural evolution and optical behavior of the thin films across varying Er3+ concentrations. The sol-gel demonstrated effective capabilities for substantial concentrations of Er3+ oxides through doping at lower calcination temperatures. The spectroscopic characteristics were studied using visible-near infrared spectroscopy (UV–vis–NIR), transmission electron microscopy, and Fourier transform infrared spectroscopy. Increasing the Er ratio decreased both the transmission and the energy band gap (3.6–3.34 eV) of the films while the absorption peak increased. The obtained results suggest that Er3+ activators demonstrate advantageous optical properties in the evaluated sodium silicate glass matrix. With the introduction of Er, optical transmittance ranges from 85 to 55% in the visible and near-infrared (NIR) regions, highlighting their advantageous characteristics. This research contributes to advancing the understanding of erbium-doped thin films for potential applications in optoelectronic devices and photonics.