Optical manometry provides noncontact pressure sensing but remains vulnerable to temperature-induced drift, where thermal expansion and nonradiative relaxation distort luminescence spectra and kinetics. We develop a spectro-temporal ratiometric approach that combines spectral and time-gated luminescence channels to decouple pressure and temperature responses and realize thermally invariant optical manometry. Using Y3In2Ga3O12:Cr3+ as a rigid-lattice host (Dq/B ≈ 2.2), lattice stiffness minimizes thermal sensitivity SR,T, while ratiometric detection stabilizes pressure sensitivity SR,p. The resulting thermal-invariance manometric factor (TIMF) = SR,p/SR,T reaches ≈7700K·GPa-1 in the spectral domain and ≈2500 K·GPa-1 in the time-gated domain, with SR,p up to 51%·GPa-1. These values exceed ruby benchmarks by two orders of magnitude and surpass conventional lifetime analysis by ∼40 times, enabling accurate, self-referenced optical pressure mapping under extreme thermo-mechanical conditions. This work provides luminescent manometry from empirical calibration to a quantitative framework for thermally reliable sensing in coupled fields.

The development of reliable luminescent nanothermometers for cryogenic applications is essential for advancing quantum technologies, superconducting systems, and other fields that require precise, high-spatial-resolution temperature monitoring. Lanthanide-doped systems are vastly employed to this purpose, and typically perform optimally at or above room temperature when manifold-to-manifold transitions are used. In this work we exploit individual Stark sublevels to demonstrate an optical Boltzmann thermometer based on Er3+/Yb3+ codoped yttria (Y2O3) nanoparticles that operates effectively across the temperature range from 25 to 175 K. This is achieved due to the pronounced crystal field environment of the Y2O3 host matrix, leading to well-separated Stark lines in the luminescence spectrum of the Er3+ ions. By applying the Luminescence Intensity Ratio (LIR) method to transitions originating from two Stark components of the 4S3/2 manifold of the Er3+ ions, we achieve thermal sensitivities up to 1.22% K-1 at 100 K and temperature resolutions reaching 0.6 K. Our results further experimentally confirm recently published theoretical predictions, demonstrating that thermometric performance is not directly dependent on the peak energy separation of the resulting spectral lines of the involved electronic energy levels when using individual Stark transitions to evaluate the LIR. The proposed procedure gives an energy gap calibration that matches the one determined by sample spectroscopy for nonoverlapping lines in the luminescence spectrum. These insights provide a robust foundation for the design of high-performance cryogenic thermometers based on rare-earth-doped materials.

High-quality seed material is a critical factor in the efficient production of grain and its products. Producing high-quality products requires more plant protein, a source of which is chickpeas. Quality control, which can be accomplished using optical methods, is of great importance when storing grain and seeds. The purpose of the current study was to validate the selection of informative spectral parameters to develop a photoluminescence diagnostic method for chickpeas. There were studied the optical spectral luminescence properties of middle-maturing chickpeas ‘Pamyat’ harvested in 2024, 2019, and 2017. Optical measurements were performed using a diffraction spectrum fluorimeter ‘CM2203’. There have been obtained excitation (absorption) and luminescence spectra. Chickpea excitation was in the range of 250–550 nm, with maxima at 362 and 424 nm for all samples studied. The greatest difference in the integral absorption parameter was in the excitation range of 370–500 nm. There were obtained integral parameters of the luminescence spectra at excitation wavelengths of 362 and 424 nm. Integral photoluminescence fluxes depended on storage time and percentage of protein and oil in seed. The error in determining the fluxes did not exceed 4.5 %. The most informative excitation wavelength was selected based on the condition of the maximum photo signal level, minimum error in determining the flux, and the greatest flux increase for different values of protein and oil percentage. The optimal excitation wavelength was 424 nm. The photoluminescence emission detection range for this excitation wavelength was 480–650 nm. The results obtained could form the basis to develop a photoluminescence method for monitoring chickpea parameters during long-term storage.

Abstract: Heterocyclic ligands and their metal complexes have received much attention from biochemists due to their potential bioactivities and wide applications in medicinal chemistry. In this study, four benzothiazolyl azo ligands and their zinc(II) azo complexes were synthesized and characterized by various spectroscopic techniques, such as mass spectroscopy, FTIR, NMR, and UV-vis. Their photophysical properties were studied by electronic and luminescent spectra. These zinc(II) complexes exhibited near-infrared emission at 690–900 nm precisely. Based on the received spectral data, a distorted tetrahedral geometry was suggested for all the zinc(II) azo complexes. The antimicrobial activity of the obtained azo compounds was estimated against gram-positive bacteria. All the zinc(II) chelates exhibited effective activity against S. aureus. The cytotoxic ability of the prepared azo compounds was evaluated against human cancer cell lines, i.e., hepatic cancer cells (HepG-2) and lung carcinoma cells (A549). The observed cytotoxic data showed that all prepared azo compounds exhibited a promising antitumor activity against the studied cancer cells with their IC50 values < 50 μg/mL. The benzothiazolyl azo ligands were observed to have a better antitumor potential for HepG2 than A549, while their zinc(II) azo complexes exhibited a better activity for A549 than HepG2. result: These zinc(II) complexes have possessed the near infrared emission at 690 – 900 nm preciously. All the zinc(II) chelates exhibited effective activity against S. aureus. The observed cytotoxic data showed that all prepared azo compounds exhibited a promising antitumor activity against studied cancer cells with IC50 < 50 µg/mL.

Modification of photoluminescence spectra through doping is a crucial strategy for enhancing optical performance, thereby expanding the applicability of luminescent materials across diverse fields. In particular, single-band upconverted near-infrared (NIR) emissions, though challenging to be achieved, are highly desirable for applications in data encryption, anticounterfeiting, and bioimaging. Herein, we present an effective approach to manipulate the energy distribution across the different excitation states of Tm3+ by constructing Mn2+-mediated energy transfer (ET) bridges. The incorporation of Mn2+ significantly enhances the upconversion (UC) NIR emissions of Tm3+, while simultaneously suppressing the competing visible transitions. This engineered redistribution directs the excited-state energy from the higher to lower energy levels in Tm3+, culminating in exclusive single-band NIR output. The underlying UC ET mechanisms have been systematically investigated through steady-state and transient luminescence analyses, revealing two distinct ET bridges that regulate the electron population probabilities across the excitation states of Tm3+. Furthermore, the detailed ET pathways have been elucidated and identified using quantum-cutting-based cross-relaxation models. As a result, the optimized UC excitation-emission system, driven solely by NIR light, demonstrates promising potential for information encryption and multimode anticounterfeiting. This study demonstrates a practical strategy for finely tuning luminescence spectra, thereby facilitating the development of multifunctional luminescent materials.

Inner filter effect regulated upconversion sensing platform for non-invasive detection of two gastric cancer relevant substances.

Manganese(II) halide complexes with the general formula [MnX2{(PhN=PPh2)CH2}], where X is bromine or iodine and (PhN=PPh2)CH2 is the bis-phosphanimine ligand 1,1′-methylenebis-(N,1,1-triphenylphosphanimine), were prepared and isolated. The structure of the two compounds was determined by single-crystal X-ray diffraction, revealing an approximately tetrahedral geometry at the metal centre. Unlike structurally comparable compounds containing phosphine oxides or related [O=P]-donors in the coordination sphere, which commonly show green emissions, solid samples of [MnBr2{(PhN=PPh2)CH2}] and [MnI2{(PhN=PPh2)CH2}] exhibited orange emissions upon irradiation with UV light. The emission spectra resulted excitation-independent. Superimposable steady-state luminescence spectra were collected for both compounds as powders and crystals suitable for X-ray diffraction. The excitation spectra and the ligand→metal antenna effect were affected by the coordinated halide, and only [MnBr2{(PhN=PPh2)CH2}] showed bright luminescence under near-UV irradiation. Either ligand- or metal-centred transitions can account for the observed luminescence, and the luminescence decay curves were consistent with a multiplicity change from the excited to the ground state, with excited-state lifetimes in the range of hundreds of microseconds. Attempts to rationalize the unexpected luminescence were carried out based on DFT calculations.

In the development of multifunctional materials, symmetry selection rules often exert opposing influences on luminescence and magnetic memory performance. For lanthanoid single-molecule magnets (SMMs), large crystal field splitting or high-symmetry environments are generally advantageous, as they suppress wavefunction mixing and minimize fast relaxation pathways-both essential for achieving slow magnetic relaxation. Conversely, these same selection rules often hinder luminescence in lanthanoid complexes, resulting in low quantum yields and frequently necessitating the use of the antenna effect, in which excitation occurs via a coordinating ligand. Here we report the subtle influence of ligand substitution in the related families of lanthanoid complexes: [Ln(tpa)(NO3)3] (1-Ln) and [Ln(tpa)Cl3] (2-Ln) (tpa = tris(2-pyridylmethyl)amine; Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb). Despite the change in ligands, similar pseudo-symmetries are found for both 1-Ln and 2-Ln, yielding closest agreement to the C3 point group. In-field slow magnetic relaxation is observed for 1-Gd, 2-Gd, 2-Dy, 1-Yb and 2-Ybvia ac magnetic susceptibility studies. Slower magnetic relaxation is found for 2-Gd and 2-Yb relative to their corresponding counterparts with computational studies validating larger crystal field splitting and increased ground state purity for 2-Yb and 2-Dy, consistent with the observed behaviour. Interestingly, the highly mixed ground state wavefunction for 1-Dy correlates with the absence of SMM behaviour, owing to the bidentate nature of the nitrato ligands, shifting ligand donor atoms away from the ideal axial position. The luminescence spectra for 1-Eu and 2-Eu both display splitting patterns of the 5D0 → 7FJ peaks consistent with a trigonal coordination environment. The luminescence decays indicate longer lifetimes for 1-Eu, which is ascribed to enhanced non-radiative decay for 2-Eu, following determination of similar radiative lifetime values for both complexes. This study highlights how subtle variations in lanthanoid coordination symmetry modulate both SMM and luminescence properties.

New compounds based on cytisine and coumarin are of interest to the pharmaceutical industry due to their promising biological activity. This activity, in turn, is closely related to the structure of the compound, which is manifested in its specific electronic properties. This paper presents the results of a theoretical study of the electronic and structural properties of recently synthesized N-(2-oxo-2H-chromen-3-carbonyl) cytisine. The molecular structure of the ground and first excited states is established. Their structural features are considered, taking into account their conformational diversity. The probabilities of vertical electronic transitions, which determine the intensities of bands in the emission spectrum, are calculated. The obtained theoretical results are compared with the measured luminescence spectrum of ethanol solution.

Light-emission devices based on InGaN/GaN quantum well (QW) bring about an ongoing revolution in general lighting. One of the highly deliberated discussions in this field is the steep efficiency drop with the increasing indium content of InGaN/GaN QW, posing a critical challenge to InGaN-based long-wavelength optoelectronic devices. Unfortunately, the factors that underlie the limitation remain unclear. Here, by using femtosecond transient absorption spectroscopy, we investigate the carrier dynamics of InGaN/GaN QW and find that the luminescence efficiency of InGaN/GaN QW is closely related to the localization states (LSs), i.e., dot-like In-rich InGaN clusters, in the InGaN layer. We demonstrate that the increase in the indium content can not only decrease the potential depth of LSs to weaken the localization binding effect and enhance the possibility of electrons being trapped by defects, but also enhance the density of LSs to increase the recombination channels and enlarge the full width at half maximum of the luminescence spectra. With these findings, we propose a model of carrier dynamics to deeply understand the emission mechanisms of InGaN/GaN QW, paving a way towards realizing high-performance InGaN-based optoelectronic devices.

The multiplicity character in luminescence spectra of highly symmetrical pyrene molecules dissolved in different matrices and solvents was investigated. Using the LCAO methods, the electron density distributions in the ground and excited states of the pyrene molecule were determined, which made it possible to explain the doublet structure in the pyrene luminescence spectra. The doublet structure analysis was based on an idea about the existence of two equivalent groups, composed of carbon atoms with maximum electron density in the orbitals of the ground and first excited states of the pyrene molecule. The calculated data were compared with the experimental results.

LiNbO3:Eu) nanoparticles with a pronounced defect structure, including crystalline and amorphous substructures. It was found that defects induced by the synthesis process lead to synergistic modification of the optical and photocatalytic properties of the material. The Raman spectrum of the nanoparticles revealed significant broadening of lines corresponding to fundamental vibrations of Li+ and Nb5+ ions along the polar axis of the crystal. Significant spectral deformation and the appearance of new lines are observed in the region of vibrations of the oxygen framework of the structure (500-1000 cm-1). The photoluminescence spectrum also revealed a strong broadening of the luminescence bands of Eu³+ ions compared to the bulk crystal. A forbidden ⁵D₀ → ⁷F₀ transition at 579 nm was detected in the luminescence spectrum, indicating a violation of the centrosymmetry of the local environment of europium ions due to disordering of the crystalline matrix structure. The nanoparticles exhibit pronounced photocatalytic activity in the decomposition of methylene blue under simulated solar radiation, with a twofold increase in reaction rate constants compared to photolysis. The role of defects in the efficient separation of photoinduced charges and the generation of reactive oxygen species is discussed, as is the potential of Eu3+ centers as probes for monitoring catalytic processes. The obtained results lay the foundation for the development of a new class of multifunctional nanomaterials in which luminescent and catalytic properties are optimized through targeted defect engineering.

ZnO-benzimidazole composite for selective detection of Zn2+ and Mg2+ ions.

We report the design and self-assembly of supramolecular nanohybrids composed of a lipophilic zinc porphyrin dimer (ZnP)2 and diblock copolypeptide amphiphiles. The peptide amphiphiles were designed with hydrophilic segments containing aspartic acid (Asp) and lysine (Lys) residues that favor β-sheet formation and hydrophobic segments composed of leucine (Leu) residues that drive aggregation in aqueous media. This balance of hydrophobic and hydrophilic interactions promotes the spontaneous formation of nanostructures such as vesicles and lamellae in aqueous media, resulting in highly organized hybrid assemblies. UV-vis absorption and fluorescence spectroscopy revealed that the interaction between (ZnP)2 and the peptides significantly affects the conformation of the porphyrin units. Absorption spectra showed shifts in the B (Soret) and Q bands upon hybridization, reflecting changes in π-conjugation and planarity. Fluorescence emission spectra, particularly those excited at the B band (443 or 494 nm), displayed a distinct band around 741 nm, attributed to the planar conformation of (ZnP)2. The corresponding excitation spectra matched well with the absorption features of planar (ZnP)2, confirming the selective excitation of these conformers. Spectroscopic analyses, including IR and circular dichroism spectroscopy, reveal that the polypeptide components adopt β-sheet-rich secondary structures, which play a critical role in inducing and stabilizing the planar conformation of the embedded (ZnP)2 units. Importantly, the planar conformation of (ZnP)2 is induced by strong intramolecular exciton coupling between the porphyrin chromophores, as evidenced by distinct luminescence spectra in the near IR region. Moreover, the incorporation of Asp residues into the hydrophilic domain further promotes β-sheet formation, contributing to the structural integrity and water solubility of the nanohybrids, leading to intermolecular interactions between (ZnP)2s in copolypeptide amphiphiles. These results demonstrate that cooperative self-assembly of metal complexes with sequence-defined polypeptide amphiphiles enables the emergence of dynamically responsive and functional supramolecular materials in water, offering new design principles for optoelectronic and bioinspired nanomaterials.

Persistent luminescence refers to a delayed emission of light that predominantly occurs in semiconductors and insulators with large bandgaps [1]. The phenomenon is characterized by the presence of electronic energy levels that can act as traps for excited charge carriers. When these traps are filled upon irradiation with high-energy photons, persistent luminescence can last for extended periods at ambient temperatures. The release of charge carriers from their traps is highly temperature-dependent, making such phosphors excellent candidates for luminescence thermometry applications [2].Thermoluminescence-based temperature measurements offer a non-invasive, high-resolution method of monitoring temperature changes, even in living cells under physiological conditions [3]. This capability is invaluable in various fields, including biomedical diagnostics and treatments. Specifically, the integration of thermoluminescence with luminescence thermometry holds significant potential in cancer diagnostics and therapy, particularly for melanoma and breast cancer.By using perovskite-based nanomaterials, triple-doped with Cr3+ ions and carefully selected Ln3+ ions, we can formulate phosphors that emit thermoluminescent light for diagnostic purposes while simultaneously enabling the monitoring of temperature variations in specific cells or organelles. This could greatly enhance the precision of cancer treatments, facilitating targeted therapy and improving patient curing.During the presentation, the findings of our research will be discussed in detail, highlighting both the advantages and potential drawbacks of this innovative method for temperature measurement using persistent luminescence spectra. We will also discuss its future impact it could have on the development of non-invasive diagnostic tools and therapies in the medical field.[1] S. W. S. McKeever, Thermoluminescence of Solids, (1985).[2] C. D. S. Brites, P. P. Lima, N. J. O. Silva, A. Millán, V. S. Amaral, F. Palacio, L. D. Carlos, Nanoscale 4 (2012) 4799.[3] R. Piñol, J. Zeler, C. D. S. Brites, Y. Gu, P. Téllez, A. N. Carneiro Neto, T. E. da Silva,R. Moreno-Loshuertos, P. Fernandez-Silva, A. I. Gallego, L. Martinez-Lostao, A. Martínez,L. D. Carlos, A. Millán, Nano Lett 20 (2020) 6466. Acknowledgment: This research was funded by National Science Centre, Poland under OPUS grant no. 2023/49/B/ST5/04265.

The development of luminescence thermometry has emerged as a compelling frontier in materials science, offering non-invasive, remote, and highly localized or, vice versa, surface-spread temperature sensing across diverse spatial and temporal scales. From cryogenic conditions to extreme high-temperature regimes, luminescent thermometers are finding increasing utility in environments where conventional temperature probes fail—be it in microelectronics, biological systems, or harsh industrial settings. At the heart of this progress lies the search for efficient and robust thermometric phosphors—materials whose luminescence properties sensitively and reproducibly respond to temperature variations.Among various luminescence thermometry strategies, Boltzmann thermometry remains particularly attractive due to its elegant physical basis. In this approach, the thermal population distribution between two thermally coupled energy levels of a luminescent ion is governed by Boltzmann statistics, and the ratio of the emission intensities originating from these levels can be directly correlated with temperature. This method offers inherent advantages such as self-referencing behavior, eliminating the need for external calibration standards, and often provides a linear response over broad temperature ranges. However, despite the conceptual simplicity and the growing number of materials reported as Boltzmann thermometers, significant gaps remain in our understanding of what determines their sensitivity, operating range, and stability.This contribution aims to critically explore the current landscape of luminescent Boltzmann thermometry with a focus on the underlying physicochemical factors that govern its performance. In particular, we highlight the need to better recognize and systematically investigate the role of the host lattice—often treated as a passive backdrop—in modulating the thermometric behavior of the activator ions. We argue that the host lattice is far from being a neutral scaffold and may, in fact, play an active role in enabling or suppressing efficient thermometric performance.One pivotal, yet underappreciated factor in this context is the phonon energy spectrum of the host lattice. While the general influence of host phonons on nonradiative relaxation processes has been widely acknowledged in luminescence studies, their specific impact on the functionality of Boltzmann thermometers has not been sufficiently dissected. High-energy lattice vibrations can facilitate thermally assisted nonradiative transitions, thereby altering the effective thermal coupling between energy levels. They may even modify the relative radiative rates, directly impacting the intensity ratios upon which Boltzmann thermometry relies. Moreover, phonon interactions may influence the thermal population mechanisms beyond simple Boltzmann statistics, especially when additional thermally accessible electronic or vibronic states are present or become activated at elevated temperatures.We will also present a selection of case studies involving host lattices with continuously decreasing phonon energies without changing their crystal structure to trace the effect on the luminescence spectra of Pr3+ and their temperature dependence. We shall see that seemingly subtle variations in host composition can lead to pronounced differences in thermometric response. These examples will help to underline the complexity of selecting or designing new phosphors for luminescence thermometry: a process that must go beyond empirical trial-and-error toward a more theory-informed, materials-by-design paradigm. Acknowledgments: This research was funded by the Polish National Science Centre, NCN, under the grant OPUS UMO-2023/51/B/ST5/02341. Figure 1

The absorption spectra and pulsed cathodoluminescence of solid phenol were recorded during irradiation with a pulsed electron beam of 2 ns duration with an average electron energy of 170 keV. The maximum number of exposure pulses was 4000 at a repetition rate of 1 Hz and a maximum absorbed dose per pulse of 1.38 kGy. Four bands were distinguished in the luminescence spectrum. A strong band at 375 nm is associated with the T1®S0 transition, at the long-wave edge of which less intense bands are observed at 395 and 475 nm and are associated with the transition from T1 to vibrational levels of the S0 state. The long-wave band at 740 nm is formed by the triplet-triplet (Ti®T1) transition. The behavior of the intensities of all luminescence bands depending on the number of irradiation pulses has a specific character. Initially, the band intensity increases until it reaches a maximum, but after that, an exponential decline occurs due to the transformation of phenol. This process begins with the cleavage of the OH bond, resulting in the formation of a phenoxyl radical, the oxidation of which leads to the formation of benzoquinones, which interact with phenol to form complex compounds.

In the aspect of water purification, a photoactive hybrid material based on reduced graphite oxide (RGO) with covalently, coordinatively, and through van der Waals interactions bonded zirconium(IV) phthalocyanine (PcZr) is proposed. In the material, the phthalocyanine complex plays the role of photosensitizer, while RGO is considered a carrier, ensuring high surface area and supporting PcZr activation. The central metal atom of PcZr directly interacts with lateral active oxygen-containing surface groups of graphite oxide, mainly –OH and –COOH. Thus, the proposed method of synthesis under solvothermal conditions allowed obtaining a relatively high concentration of the dye (0.2 wt.%) in the system based on a partially reduced and exfoliated graphite oxide. Optical studies confirmed the presence of PcZr through absorption and luminescence spectra. Additionally, effective generation of reactive oxygen species was demonstrated by testing the transformation of a dye indicator (diphenylisobenzofuran). Photocatalytic activity of the system was confirmed by photooxidizing selected organic dyes (methylene blue, Rhodamine B, Brilliant Green, and Eriochrome Black T) in a water medium, tested in slightly acidic conditions under red light. The greatest overall decrease in absorption during the photodegradation test was observed for Brilliant Green, reaching 88% after 3 h of irradiation.

This study aims to (1) determine the synthesis of carbon nanodots nanomaterials made from wedang uwuh, (2) determine the characterization of carbon nanodots nanomaterials made from wedang uwuh using UV-Vis, PSA, and PL spectrophotometer tests, (3) determine the effect of low-temperature carbonation methods with oven heating time variations on the gradation of luminescence spectra in carbon nanodots nanomaterials made from wedang uwuh from the results of UV laser irradiation. This research consists of three stages, namely synthesis, shooting, and characterization. This research is made from wedang uwuh with oven heating method. The results of the shooting show the occurrence of color gradation from yellow to cyan luminescence. UV-Vis results show absorbance peaks at oven heating time variations of 0, 15, 30, 25, and 60 minutes of 266, 269, 273, 279, and 280 nm respectively indicating a red shift at the peak absorbance of carbon nanodots. PL results show a blue shift with emission peaks at wavelengths of 574 nm glowing yellow, 529 and 518 nm glowing green, and 494 and 489 nm glowing cyan. PSA results show that the longer the oven heating time, the smaller the particle size of carbon nanodots.

The access to various [n]helicenes holds significant values in synthetic chemistry and materials science due to the unique helically chiral structures and potential applications in chiroptoelectronic materials. Particularly, one of the challenges and current interests as well in this area is to construct new chiral systems that can promise intriguing light-emitting properties and long-wavelength circularly polarized luminescence (CPL). In general, the luminescence and CPL spectra have proved to be effectively tuned into the far-red and near-infrared (NIR) regions with reasonably high emission quantum efficiency via extension of π-conjugation or fused-ring expansion. As the other proof-of-concept, heteroatom doping of main-group elements (e.g., O, S, N, B) has also served to enable the precise modulation of molecular electronic structures with reduced HOMO-LUMO energy gaps, leading to the improved performance of NIR CPL. Our minireview offers an overview of rapid progress recently achieved in these emerging chiroptical materials together with extensive discussions on the design strategy and chiroptics both for carbo[n]helicenes and for hetero[n]helicenes, which may provide some new insights into the further pursuit of high-performance NIR-active chiral luminescent materials.