Visible Fluorescence Research Articles

Transition metal and lanthanide modified MOF-808 for barcode design.

This study explores the utilization of metal-organic frameworks (MOFs), particularly those incorporating lanthanide-based elements for their fluorescence capabilities, to create an advanced barcode system. By exploiting the modular nature of MOFs, we have developed a material capable of dynamic information encoding and robust against counterfeiting efforts. We introduce a novel barcode prototype that exhibits visible color shifts and fluorescence modulation when exposed to a specific sequence of chemical and thermal stimuli. The barcode is composed of MOF-808, which is modified with transition metals like iron or cobalt, and europium cations. These components are embedded within polyvinylidene fluoride (PVDF) to form a composite. This embedding process ensures that the MOF particles remain reactive to specific trigger molecules, enabling a distinct read-out sequence. The decoding process, involving exposure to ammonia, heating at 120 °C, and treatment with HCl, triggers observable changes in fluorescence and color, depending on the transition metal used. Our investigations with Eu,Co-MOF-808, and Eu,Fe-MOF-808 composites have resulted in the creation of a barcode prototype that demonstrates the feasibility of using europium-modified and unmodified transition metal modified MOF-808@PVDF composites for enhanced security applications.

Biodegradable Nanocomposite of ZnS(Mn) Quantum Dots Immobilized Graphene Oxide for Bioimaging Applications.

Developing a biocompatible and biodegradable graphene-based fluorescent nanoprobe with the ability to visualize live cells could be interesting for intracellular imaging and monitoring the efficiency of chemotherapy. Herein, we report a biodegradable and biocompatible hybrid fluorescent graphene oxide (GO)-ZnS(Mn) composite synthesized via in situ growth of ZnS(Mn) quantum dots (QDs) on the surface of GO in the aqueous medium. The prepared 'GO-ZnS(Mn)' composite was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and high-resolution transmission electron microscopy (HR-TEM) along with selected area electron diffraction (SAED). Further, the fluorescence properties of the GO-ZnS(Mn) composite were studied using fluorescence emission spectroscopy. The composite material exhibited a strong and broad visible light fluorescence from 500 to 600 nm by excitation with 365 nm (UV) light. The cytotoxic experiments of folic acid (FA) conjugated GO-ZnS(Mn) using MTT [(3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide)] assay revealed that the composite had excellent biocompatibility even at higher concentrations up to 200 µg/mL in HeLa cell lines. Next, the bioimaging experiments carried out using confocal fluorescence laser scanning microscopy (CLSM) revealed that GO-ZnS(Mn) composite was taken up by the HeLa cells effectively within 12 h of incubation via receptor (folate) mediated endocytosis with strong fluorescence throughout the cell surface. Finally, the biodegradability of GO-ZnS(Mn) composite was studied by treating it with human myeloperoxidase enzyme (hMPO) isolated from the primary immune cells, neutrophils, which is important to understand the in vivo fate of GO-Zns(Mn). The HR-TEM and Raman analyses confirmed the biodegradation of GO-ZnS(Mn) within 15 h of hMPO treatment. Thus, the biodegradable GO-ZnS (Mn) composite could be helpful for chemotherapy and bioimaging applications.

Hemostatic bioactivity and mechanism of novel Rubia cordifolia L.-derived carbon dots.

Background: Rubia cordifolia L. (RCL) Carbonisata is a typical calcined natural medicinal plant, which has been used for thousands of years for hemostasis. At present, some studies have shown that some components of processed RCL Carbonisata can enhance hemostasis, but the specific hemostatic material basis is still unclear. Novel carbon dots (CDs) were obtained from Rubia cordifolia L. and named RCL-CDs to explore the hemostatic effect and mechanism of RCL-CDs obtained from Rubia cordifolia L. Methods: RCL-CDs were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet visible spectroscopy (UV-Vis), fluorescence spectroscopy (FL), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The hemostatic effect of RCL-CDs was evaluated in a mouse tail amputation model and liver scratch model, and the hemostatic mechanism was explored using a capillary coagulation model and coagulation parameters. Results: The particle size distribution of RCL-CDs ranged from 1.74 nm to 9.78 nm, the maximum population was 3-4 nm, and the average particle size was 3.82 nm. The RCL-CDs were approximately spherical with a lattice spacing of 0.206 nm. The quantum yield (QY) of RCL-CDs is 1.09%, and there is a distinct diffraction peak at 2θ = 24.76°. The elemental composition of RCL-CDs was mainly C (65.28%), O (30.10%), and a small amount of N (4.62%). Pharmacological experiments showed that bleeding time and bleeding volume were reduced in mice treated with RCL-CDs. It is worth noting that the low-, medium- and high-dose RCL-CD groups can significantly reduce the blood loss, while the high-dose RCL-CD group can significantly reduce the bleeding time of the mouse tail amputation model and liver scratch model. Additionally, the fibrinogen level (FIB) and platelet counts (PLT) increased and prothrombin time (PT) decreased in rats after treatment with RCL-CDs. Conclusions: RCL-CDs have a significant hemostatic effect, and the mechanism may be exogenous coagulation and activation of fibrinogen. This explains the material basis of the hemostatic effect of RCLC and opens new avenues for more in-depth investigation. In addition, new insights into the potential biomedical applications of CDs in the field of nanohemostasis are provided and a solid foundation for the discovery of novel hemostatic agents is established.

Characterizations and molecular docking mechanism of the interactions between peptide FDGDF (Phe-Asp-Gly-Asp-Phe) and SOD enzyme

In this study, we investigated the antioxidant properties of dry-cured beef crude peptide (BPH) at different storage periods. The combination characteristics of different concentrations of Phe-Asp-Gly-Asp-Phe (FDGDF) and superoxide dismutase (SOD) at different temperatures were analyzed by ultraviolet–visible spectroscopy, fluorescence spectroscopy, and FT-IR spectroscopy, combined with the detection of a SOD activity detection box. It was found that FDGDF could improve the activity of SOD by changing its secondary structure. Bonds were formed at O32/O40/O52 using quantum chemical simulation calculations, and the Fukui index was higher than that of most atoms, indicating that these atoms were more likely to participate in the reaction. SPR biological force analysis showed that FDGDF and SOD were in a fast binding and dissociation mode. This study revealed the theoretical basis for studying the antioxidant mechanism of dry-cured beef and provided ideas for developing new dry-cured beef products.

A novel “off–on” peptide fluorescent probe for the detection of copper and sulphur ions in living cells

The fluorescent peptide probe FGP1 quickly detects Cu2+ ions, leading to visible fluorescence quenching. The addition of S2− ions to the FGP1-Cu complex restores fluorescence, resulting in an 'off–on' process.

Study the solute-solvent molecular interactions of L-Glutamine and conventional surfactants

The micellar characteristics of the three conventional surfactants such as sodium dodecyl sulfate (SDS), Hexadecyltrimethylammonium bromide (CTAB), and Triton X-100 (TX-100) are changed by the addition biologically active L-Glutamine (Glu) (i.e., 0.005, 0.01 and 0.02 M) were determined from stalagmometric, UV–visible spectroscopy, viscometric, FTIR and fluorescence methods using pyrene as probe. An observed decrease in I1/I3 in all micellar systems confirms the relative hydrophobicity of L-Glu. The CMCs values are reduced with the addition of L-Glu were determined by stalagmometric and it is confirmed by UV–visible and fluorescence methods and differs in the following order: SDS > CTAB > TX-100. The estimation of numerous interfacial parameters have also been done by using stalagmometric measurements including the (ϒCMC), (πCMC), (pC20), (Amin), and (Гmax). The concentration of L-Glu (M) rises, Amin values rise while the Гmax value falls and a significant rise in the surface tension of CMC (ϒCMC) values, with the values being in the range of 0.02 M > 0.01 M > 0.005 M > water. Hydrogen bonds, electrostatic interactions, hydrophobic interactions, and van der Waal interactions are only a few of the diverse types of interactions that were examined using FTIR in the pure surfactants and L-Glutamine mixed systems. To stabilize proteins and prevent protein aggregation, the findings presented here may be applied in pharmaceutical formulations.

Highly selective fluorometric detection of streptokinase via fibrinolytic release of photoluminescent carbon dots integrated into fibrin clot network

This work pioneers a selective fluorometric assay for the fibrinolytic agent streptokinase by strategically coupling its thrombolytic action to fluorescence signaling using carbon dots integrated into fibrin clot network. Streptokinase triggers clot lysis and caused release of photoluminescent carbon dots integrated within the fibrin network in a concentration-dependent manner. Transmission electron microscope (TEM) imaging verifies distinct aggregation of the carbon dots upon addition to fibrin. The carbon dots are derived via an eco-friendly hydrothermal approach using cucumber peel as the source of carbon. Structural and optical characterization of the carbon dots were performed using different techniques including X-ray diffraction, TEM, Fourier-transform infrared spectroscopy, and ultraviolet–visible absorption and fluorescence spectroscopies. All experimental parameters influencing the formation of the fibrin clot and factors governing the release of carbon dots upon the addition of streptokinase have been fully optimized. This fluorescence assay offers high selectivity for streptokinase over potential interferences in addition to excellent sensitivity with a 0.017 μg/mL limit of detection and a wide linear range (0.05–500 μg/mL). Successful application to pharmaceutical formulations is demonstrated with excellent recovery and precision. By ingeniously linking streptokinase activity to carbon dot fluorescence, this novel assay provides a rapid, simple and eco-friendly method for selective streptokinase detection.

Dual-channel versatile molecular sensing platform for individual and successive HClO and H2S detection: Applicable in toxic alerts of environmental samples and living organisms

In this study, we have successfully developed a novel dual-response fluorescent probe, NACou, designed for the visual and quantitative detection of HClO/H2S in real water samples and liquid beverages by a thin-film sensing platform. Additionally, NACou demonstrated efficacy for sensing HClO/H2S in HeLa cells, plants and zebrafish through distinct fluorescent channels, yielding satisfactory results. NACou exhibited a multi-modal fluorescence response mechanism for detecting HClO and H2S with remarkable low detection limits of 27.8 nM and 34.4 nM, accompanied by outstanding fluorescent enhancement (209-fold and 148-fold, respectively). These advantages position NACou as a potent molecular tool for HClO and H2S sensing. The specific recognition performance of NACou towards HClO/H2S were confirmed through fluorescence spectroscopy, mass analysis and UV–vis spectroscopy. Importantly, the thin-film sensing platform with the visible fluorescence change can enable rapid assays for water quality and food safety monitoring, showcasing significant practical application value. Impressively, NACou has been employed in warning against liver injury induced by multiple drugs, allowing for the exploration of the pathogenesis and degree of drug-induced injury.

Studies on anionic dye Eosin Y in mixed anionic micellar medium

Dye-Surfactant interactions in aqueous solution are important in industrial processes. Generally, dyes associate strongly with oppositely charged surfactants. But, similarly charged dye-surfactants are not preferred anticipating repulsion. To gain insight into the nature and extent of interaction between anionic dye Eosin Yellow (EY) and mixed anionic micellar system, this study was undertaken. Mixed micellar system comprised of anionic, Sodium dodecyl sulfate (SDS) and nonionic Pluronic L-35 (L-35). The characterizations employed were FTIR Spectroscopy, Conductivity, UV visible spectroscopy, Fluorescence spectroscopy and SEM studies. A red shift with enhancement of intensity was observed both in UV-absorption and emission spectra of EY when interacted with SDS + L-35 mixed micellar system. From the conductance measurements, the counter ion binding constant β was calculated. Subsequently, various thermodynamic parameters viz., ΔGm, ΔHm and ΔSm were evaluated using β. The Gibbs free energy of micellization, ΔGm was observed to be −4.56 kJ mol−1, −13.34 kJ mol−1 and −18.55 kJ mol−1 for SDS, SDS + L-35 and SDS + L-35 + EY respectively. The negative values of ΔGm are indicating the spontaneous binding occurring between EY and SDS + L-35. The SEM images revealed enlargement of grain size of the mixed micelle after encapsulation of EY. To the best of our knowledge this is the first report of anionic dye EY with an anionic mixed micellar system.

Effects of nutrient addition on the composition and chemical characteristics of soil dissolved organic matter in a desert steppe in northern China

AbstractDissolved organic matter (DOM) plays a critical role in ecosystem function and productivity, particularly in carbon (C) cycling in grassland ecosystems. However, changes in the structural complexity of DOM in a desert steppe following long‐term treatment with nitrogen (N) and phosphorus (P) remain unclear; this limits our understanding of the nutrient‐related soil C cycle in a desert steppe. In the present study, soil experiments were conducted in the 0–10 cm soil layer of a desert steppe in northern China from 2017 to 2021, and four treatments were established: P, N, N + P (NP), and no nutrient addition (CK). The content and chemical composition of soil DOM were determined by ultraviolet–visible absorbance, fluorescence, and Fourier transform infrared spectroscopy. Compared to CK treatment, nutrient addition increased soil DOM content by 2.86%–53.84%. NP addition increased the average molecular weight, aromaticity, and humification degree of soil DOM. The DOM source was attributed to the combination of foreign and local sources. Fluorescent components of the DOM samples were mainly proteins and humic acids; the humic acid content decreased after N addition and increased after P and NP addition. Nutrient availability and pH were the key factors affecting the changes in the source and average molecular weight of the DOM, respectively. The soil organic matter content was significantly positively correlated with the humification index (r = 0.96). These results imply that nutrient addition accelerates the accumulation of DOM and influences its structural complexity; this potentially benefits soil C sequestration in a desert steppe.

Ratiometric fluorescence determination of alkaline phosphatase activity based on carbon dots and Ce3+-crosslinked copper nanoclusters.

A new ratiometric fluorescent probe for efficient determination of ALP was developed. The probe was constructed by combining Ce3+-crosslinked copper nanoclusters (Ce3+-CuNCs) which exhibit the aggregation-induced emission (AIE) feature with carbon dots (CDs). The introduction of phosphate (Pi) induced the generation of CePO4 precipitation, resulting in significant decrease of fluorescence emission of CuNCs at 634nm. At the same time, the fluorescence of CDs at 455nm was obviously enhanced, thus generating ratiometric fluorescence response. Based on the fact that the hydrolysis of pyrophosphate (PPi) by ALP can produce Pi, the CD/Ce3+-CuNCs ratiometric probe was successfully used to determine ALP. A good linear relationship between the ratiometric value of F455/F634 and ALP concentrations ranging from 0.2 to 80 U·L- 1 was obtained, with a low detection limit of 0.1 U·L- 1. The ratiometric responses of the probe resulted in the visible fluorescence color change from orange red to blue with the increase of ALP concentration. The smartphone-based RGB recognition of the fluorescent sample images was used for ALP quantitative determination. A novel ratiometric fluorescent system based on Ce3+-CuNCs with AIE feature and CDs were constructed for efficient detection of ALP.

Syntheses, structures and photophysical properties of Ni/Co[sbnd]Ln coordination polymers

The new Ni/Co-Ln coordination polymers (CPs), {[LnNi0.5(2,5-pydc)(ox)(H2O)x]·yH2O}n (Ln = Pr 1, Nd 2, x = 4, y = 2; Gd 3, Tb 4, Dy 5, x = 3, y = 1; 2,5-H2pydc = pyridine-2,5-dicarboxylic acid, H2ox = oxalic acid); {[Er2Ni(2,5-pydc)3(ox)(H2O)4]·2H2O}n6; {[LnCo0.5(2,5-pydc)(ox)(H2O)x]·yH2O}n (Ln = Pr 7, Nd 8, x = 4, y = 2; Tb 9, x = 3, y = 5) were successfully synthesized by the hydrothermal methods, and their crystal structures were characterized by single-crystal X-ray diffraction. With the participation of the auxiliary ligands (ox2−), the main ligands (2,5-pydc2−) adopt four coordination modes and make these polymers exhibit three kinds of crystal structures. CPs 1, 2, 7 and 8 are isomorphous and exhibit 2D layers which are further connected to form the 3D structure by hydrogen bonds. The other four CPs are bridged into the 3D network structure by 2,5-pydc2- and ox2−. All the polymers are characterized by IR spectro, Roman spectro, thermogravimetric analysis and X-ray powder diffraction. The UV–vis–NIR absorption spectra and Vis fluorescence excitation and emission spectra of nine coordination polymers are measured and analyzed. All the CPs show ligand-to-metal charge transfer (LMCT) transition emission of NiII/CoII–ligands, while some of the CPs show weak characteristic luminescence of LnIII ions.

Electrospun hydroxypropyl-β-cyclodextrin nanofibers loaded with anti-inflammatory drugs for potential therapeutic wound dressings

Electrospun cyclodextrin nanofibers as innovative drug delivery structures offer efficient, selective, and controlled drug release. In the present work, free-standing nanofibrous webs (NFs) were fabricated from inclusion complexes (ICs) between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and non-steroidal anti-inflammatory drugs (NSAIDs) using an electrospinning technique. The fabricated NSAID-HPβCD-IC-NFs were characterized by field emission scanning electron microscopy, X-ray diffraction, thermogravimetric/differential thermal analysis, ultraviolet diffuse reflectance spectroscopy, and photoluminescence analysis. Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and computational studies were carried out to characterize the NSAID-HPβCD-IC-NFs and identify the functional groups involved in the binding mechanism. The NFs showed higher thermal stability than the pure drugs due to IC formation. The ultraviolet–visible absorption and fluorescence results indicated strong interactions between the HPβCD and NSAIDs with significant association constants at 1:1 stoichiometry. The efficiency of the NFs in terms of cell biocompatibility was verified, and the NFs exhibited excellent biocompatibility, as determined by in vitro biocompatibility assay. The in vitro scratch assay confirmed that the NFs allow the rapid growth and migration of skin fibroblast cells. These results showed that these NFs could be potential candidates for wound treatment.

Multifunctional visualized electronic skin based on a solvatochromic poly (ionic liquid) ionogel

The biological skins exhibit various fascinating visual functions, such as turning red in response to strain, whitening upon hydrogen peroxide stimulation, and changing color in accordance with the environment (octopus). Inspired by these phenomena, two kinds of multifunctional visualized electronic skin (e-skin) were designed and fabricated based on a novel poly (ionic liquid) ionogel. Herein, we reported a transparent and conductive poly (ionic liquid) ionogel (P(AAm-IL)) by photopolymerizing acrylamide (AAm) with 1-vinyl-3-butylimidazolium tetrafluoroborate (ionic liquid, IL) in ethylene glycol (EG). Interestingly, P(AAm-IL) displays a solvatochromic phenomenon, and typical hydrogen-bonding acceptor solvents like acetone, methanol, and nitromethane induce a whitening effect in it. Based on this ionogel, we fabricated multifunctional strain sensors integrated with the visualized chemical sensing ability. The discoloration mechanism of the chemical sensing was detailed studied. Furthermore, by combining the P(AAm-IL) ionogel with Lithium trifluoroethane sulfonate (LiTf), the blend P(AAm-IL)-Li ionogel exhibits enhanced stretchability (>4300 %), higher conductivity (1.44 × 10−2 S·m−1), good transparency (>80 %) as well as wide operating temperature range (−20 to 80 °C). A sandwich-structured e-skin (Polypyrrole/PAAm-IL-Li/CsPbBr3-TPU) exhibiting both electro-optical dual response to strain was successfully fabricated. The luminescent e-skin not only exhibits highly sensitive electrical responses but also demonstrates visible fluorescence changes in response to external strain variations. These multifunctional visualized e-skins demonstrate great potential for applications in chemical environmental monitoring robotics, wearable electronic devices, and human–computer interaction.

Rapid and dual optical CO2-responsive polydimethylsiloxane elastomer with fluorinated cyanine dye.

We found that our optically CO2-responsive polydimethylsiloxane (PDMS) elastomer rapidly and reversibly underwent both visible and fluorescent color changes in the presence of CO2 gas. Unlike conventional optically CO2-responsive polymeric materials, it functions in totally dry gaseous conditions. The visible color and fluorescence of the elastomer sheet change after only 1 min of exposure to CO2, and the sheet exhibits excellent repeatability in terms of color switching that persists for at least 20 times.

4,4′,4″-(Benzene-1,3,5-triyltris(ethyne-2,1-diyl))tris(1-methylpyridin-1-ium) Iodide

Despite having been known for a long time, quaternary 4,4′-bipyridinium salts, or viologens, are still a highly inspiring class of compounds, thanks to their peculiar redox and charge transfer properties. However, more complex structures containing multiple pyridinium rings, also interspaced by conjugated moieties, allow an even wider synthetic variability and tunability of their characteristics. The compound described herein is a star-shaped, fully conjugated molecule with three methylated pyridinium rings connected by a triple bond spacer to a central benzene core, which was synthesized from readily available building blocks, representing a quite simple model of multi-pyridyl extended viologen; its UV–visible absorption and fluorescence spectra have also been investigated.

Bioinspired, vertically stacked, and perovskite nanocrystal-enhanced CMOS imaging sensors for resolving UV spectral signatures.

Imaging and identifying target signatures and biomedical markers in the ultraviolet (UV) spectrum is broadly important to medical imaging, military target tracking, remote sensing, and industrial automation. However, current silicon-based imaging sensors are fundamentally limited because of the rapid absorption and attenuation of UV light, hindering their ability to resolve UV spectral signatures. Here, we present a bioinspired imaging sensor capable of wavelength-resolved imaging in the UV range. Inspired by the UV-sensitive visual system of the Papilio xuthus butterfly, the sensor monolithically combines vertically stacked photodiodes and perovskite nanocrystals. This imaging design combines two complementary UV detection mechanisms: The nanocrystal layer converts a portion of UV signals into visible fluorescence, detected by the photodiode array, while the remaining UV light is detected by the top photodiode. Our label-free UV fluorescence imaging data from aromatic amino acids and cancer/normal cells enables real-time differentiation of these biomedical materials with 99% confidence.

Evaluating the binding ability of promethazine hydrochloride drug with sodium dodecylsulphate/sodium lauroylsarcosinate/sodium cholate in the company of uridine biomolecules: experimental and theoretical approach

The appraisal of drug–surfactant binding interactions is pharmacologically and pharmaceutically noteworthy. The simple model compounds of nucleic acids such as nucleic acid bases/nucleosides are key biologically active molecules useful for studying interactions of nucleic acids with other components in bio-fluids. Therefore, the binding studies of promethazine hydrochloride (PMT) drug with individual surfactants such as sodium dodecylsulphate (SDS, anionic surfactant), sodium lauroylsarcosinate (SLS, amino based-surfactant), and sodium cholate (NaC, trihydroxy bile salt), and their mixed systems (PMT + SDS/SLS/NaC) at mole fractions, α PMT = 0.02, 0.04, 0.06, and 0.08 have been accomplished in water and 0.025 mol kg−1 aqueous uridine (nucleoside) solutions at temperatures (298.15, 308.15, and 318.15) K. Thermodynamic characteristics of micellization have been obtained from the conductivity studies. Binding constants (K b, K f) and standard Gibbs free energies of binding (ΔG ο b, ΔG ο f) for pure PMT drug and its mixed systems with anionic surfactants were evaluated from UV–visible absorption and fluorescence emission studies. Further, the density functional theory (DFT) calculations for studied systems were carried out to get net stabilization energies for the drug–surfactant complexes. NBO and HOMO–LUMO analyses were also carried out in the absence/presence of uridine. Dynamic light scattering study was used to measure the hydrodynamic diameters in micellar systems. The major influences of hydrophobic–hydrophobic interactions among the hydrophobic groups and electrostatic (ionic and H-bond) interactions among the hydrophilic/ionic groups of PMT drug, SDS/SLS/NaC, and uridine have been depicted from the present investigations.

Emission enhancement of Eu3+ doped Ba2Zn(BO3)2 by adding charge compensators

Ba2Zn(BO3)2: xEu3+ (0.001≤x ≤ 0.30), Ba2Zn(BO3)2: 0.15Eu3+, 0.05R+ (RLi, Na, K) and Ba2Zn(BO3)2: 0.15Eu3+, yK+ (0≤y ≤ 0.07) phosphors were prepared by high-temperature solid-phase method. The structure, photoluminescence (PL) and other characteristics of the prepared phosphors were studied by X-ray diffraction, ultraviolet–visible spectroscopy, PL spectroscopy and fluorescence lifetime. The concentration quenching mechanism of Eu3+ emission in Ba2Zn(BO3)2 host was investigated. In order to improve the PL performance of Ba2Zn(BO3)2: 0.15 Eu3+ phosphor, the effect of Li+, Na+ and K+ compensators on the PL performance of Ba2Zn(BO3)2: 0.15 Eu3+ luminescent powder was studied. Under excitation at 393 nm, a strong red emission peak is observed at 620 nm. This peak corresponds to the 5D0→7F2 transition and significantly increases its strength by adding a charge compensator. Therefore, the addition of K+ is very effective in improving the PL performance of Ba2Zn(BO3)2: 0.15 Eu3+ phosphors.

Inclusion phenomenon of β-carboline alkaloids with sulfonatocalix[4]arene: Photophysical, cytotoxicity and theoretical study

β-carbolines are nonpolar heterocyclic aromatic amines known as Harman and Norharman. Harman and Norharman, with anticancer effects, have recently attracted much attention but have experienced difficulty in their pharmacological development due to their low oral bioavailability. In this article, we describe the complexation of Harman (H) and Norharman (NH) with p-sulfonatocalix[4]arene (SCX4) as a feasible option to improve its solubility and, as a result, improve the cytotoxic effect on cell lines. Spectroscopic techniques, such as UV–visible absorption, fluorescence, FT-IR, FE-SEM, HRMS, NMR techniques, and molecular docking calculations, were used to analyze these inclusion complexes H ⊂ SCX4 and NH ⊂ SCX4. UV–visible absorption and steady-state fluorescence spectroscopy were used to investigate the interaction between Harman and Norharman with p-sulfonatocalix[4]arene (SCX4). A simple and precise HPLC-based approach has assessed the retention times of H, NH, SCX4, and its complexes. Additionally, an in vitro cytotoxicity study revealed that the synthesized complexes were not toxic to the mouse embryonic fibroblast (3 T3-L1) cell line. Therefore, the present study confirmed that the H ⊂ SCX4 and NH ⊂ SCX4 complexes are readily soluble in an aqueous medium that does not cause toxicity in the primary cell line and might provide a feasible option for increasing the solubility of these class of poorly soluble drugs.