High Luminescence Quantum Yield Research Articles

Preparation and Properties Study of CsPbX3@PMMA Luminescent Resin.

Perovskite as an emerging semiconductor luminescent material has attracted widespread attention due to its simple preparation, high luminescence quantum yield, high color purity, tunable spectrum, and ability to cover the entire visible light band. However, due to the influence of water or other highly polar solvents, oxygen, temperature, and radiation, perovskite nanocrystals will aggregate or collapse in the lattice, eventually leading to luminescence quenching. This study starts from the postprocessing of perovskite, uses methyl methacrylate as the monomer and TPO as the photoinitiator, and encapsulates the perovskite powder prepared by the hot injection method through ultraviolet light initiation. A method is proposed to improve the luminescence and crystal structure stability of perovskite. By eliminating the influence of environmental factors on perovskite nanocrystals through the dense structure formed by organic polymers, the resistance of perovskite to strong polar solvents such as water will be greatly improved, and it has great potential in the protection of perovskite. Finally, by changing the proportion of halogen elements in the perovskite resin to change the color of the luminescent resin, a fluorescent coating emitting light in all visible light bands is prepared. Fluorescent coatings are widely used in life and industry fields such as plastics, sol, and paper.

Preparation and properties of circularly polarized long-lived fluorescent liquid crystal materials based on TS-FRET mechanism

Circularly polarized long-lived fluorescent materials show unique application values in circularly polarized organic light-emitting diodes, advanced anti-counterfeiting materials, and so forth. However, the circularly polarized long-lived fluorescent materials with large luminescence dissymmetry factor (glum) values and long fluorescence lifetime are rarely reported. In this article, we propose to prepare circularly polarized long-lived fluorescent materials based on triplet-to-singlet Förster-resonance energy transfer (TS-FRET) mechanism. We have prepared circularly polarized long-lived fluorescent luminescent materials with large glum values, long fluorescence lifetime, high luminescent quantum yield and large Stokes shift by blending chiral room temperature phosphorescent liquid crystal Chol-C6-DF with achiral fluorescent component Br–C6-Nap. Attributed to the effective TS-FRET process between Chol-C6-DF and Br–C6-Nap, the obtained doped films show long fluorescence lifetime. When the doping amount of Br–C6-Nap is 2 wt%, the fluorescence lifetime can achieve 103 ms. All obtained doped films exhibit high glum values attributed to selective reflection of chiral liquid crystals. As the doping amount of Br–C6-Nap increases, the |glum| value first increases and then decreases, with a maximum of 1.45. In addition, the doped films also possess high solid-state luminescence quantum yield and large Stokes shift, with a maximum value of 54 % and 284 nm, respectively.

Deuterated Multiple‐Resonance Thermally Activated Delayed Fluorescence Emitter and Their Application in Vacuum‐Deposited Organic Light‐Emitting Diodes

AbstractMultiple‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters have garnered significant attention in recent years due to their remarkable properties, such as high luminescent quantum yield, robustness, and their compliance with the Broadcast Television 2020 standard for the new generation of ultrahigh‐definition. Despite these advancements, the operational lifetimes of organic light‐emitting diodes (OLEDs) relying on MR‐TADF emitters still fall short for practical application. It is believed that the enhancement of the intrinsic molecular stability of tBu‐DABNA, a fundamental backbone of MR‐TADF emitters, holds great promise to be a universal strategy for all MR‐TADF emitters improving the operational lifetimes of OLEDs. Herein, the design and synthesis of targeted deuteration are reported on donor and/or backbone of MR‐TADF emitters, where the structure‐property relationship between intrinsic molecular stability upon isotopic effect and device operational stability are examined. The isotopic analogs show a gradual increase in the device operational stability and achieve long‐lifetime LT80 (80% of the initial luminance of 1000 cd m−2) of 24.3 h for TADF‐sensitized fluorescence OLED, representing a sevenfold enhancement when compared with the undeuterated counterpart. This strategic deuteration approach underlines the importance of structural modification on materials toward device operational stability.

Efficient Quasi-2D Perovskite Based Blue Light-Emitting Diodes with Carbon Dots Modified Hole Transport Layer.

Quasi-2D perovskites based blue light-emitting diodes (LEDs) suffer from its poor electroluminescence performance, mainly caused by the nonradiative recombination in in defect-rich low-n phases and the unbalanced hole-electron injection in the device. Here, we developed a highly efficient quasi-2D perovskite based sky-blue LEDs behaving recorded external quantum efficiency (EQE) of 21.07% by employing carbon dots (CDs) as additives in the hole transport layer (HTL). We ascribe the high EQE to the effective engineering of CDs: (1) The CDs at the interface of HTLs can suppress the formation of low-efficient n = 1 phase, resulting a high luminescence quantum yield and energy transfer efficiency of the mixed n-phase quasi-2D perovskites. (2) The CDs additives can reduce the conductivity of HTL, partially blocking the hole injection, and thus making more balanced hole-electron injection. The CDs-treated devices have excellent Spectral stability and enhanced operational stability and could be a new alternative additive in the perovskite optoelectronic devices.

Reviewing the effect of aggregates in Rhodamine 6G aqueous solution on fluorescence quantum efficiency

Rhodamines constitute a class of dyes extensively investigated and applied in various contexts, primarily attributed to their high luminescence quantum yield. This study delves into the impact of aggregation on the thermal and optical properties of Rhodamine 6G (R-6G) solutions in distilled water. Examined properties encompass thermal diffusivity (D), temperature coefficient of the refractive index (dn/dT), fluorescence quantum efficiency (η), and energy transfer (ET). These parameters were assessed through thermal lens (TL) and conventional absorption and emission spectroscopic techniques. The dimerization of R-6G solutions was revisited, revealing that an increase in R-6G concentration alters the features of absorption and emission spectra due to dimer formation, resulting in unexpected behavior of η. Consequently, we introduce a novel model for the fraction of absorbed energy converted into heat (φ), which accounts for emissions from both monomers and dimers. Employing this model, we investigate and discuss the concentration-dependent behaviors of η for monomers (ηm) and dimers (ηd). Notably, our findings demonstrate that ηm values necessitate ηd = 0.2, a relatively substantial value that cannot be disregarded. Additionally, applying the Förster theory for dipole–dipole electric ET, we calculate microparameters for ET between monomers (CDD) and monomer–dimer (CDA). Critical ranges for ET in each case are quantified. Microparameter analysis indicates that ET between monomer–monomer and monomer–dimer species of R-6G dissolved in distilled water holds significance, particularly in determining ηm. These results bear significance, especially in scenarios involving high dye concentrations. While applicable to R-6G in water, similar assessments in other media featuring aggregates are encouraged.

Thermoregulated CPL‐Active Flexible Polymer/Perovskite Hybrid Materials with High Luminescence Dissymmetry Factor

AbstractCPL‐active flexible materials with high luminescence dissymmetry factor (glum) and luminescent quantum yield are indispensable for 3D displays, wearable devices and so on. Perovskite has drawn much attention due to its fascinating photoelectric properties as well as its abundant applications. However, the existing strategies are inefficient in acquiring perovskite NCs with high glum. In this work, thermoregulated CPL‐active flexible polymer/perovskite hybrid materials with high glum by the creation of chiral photonic bandgap in polymer film with cholesteric domains using toluene as the dielectric media is reported. Based on selective CPL reflection, a satisfied CPL with a maximum glum of 0.6 is achieved. Importantly, the chiral photonic bandgap center of the polymer film can be easily tuned by thermal annealing at different temperatures to adapt various perovskite NCs with full‐spectral emission. The handedness of CPL of hybrid materials can be regulated with and without dielectric media. The presence of the flexible polymer makes hybrid materials a candidate to achieve patterned display applications. Additionally, the polymer/perovskite hybrid materials show excellent stability thanks to the encapsulation effect from polymers. This work provides a facile and general approach to induce adjustable CPL in the whole visible spectrum with high glum and photoluminescence quantum yield (PLQY).

High-contrast multi-surface imaging of latent fingerprints using color-tunable YOF:Tb3+,Eu3+ ultrafine nanophosphors with high quantum yield.

Visualization of latent fingerprints (LFPs) using conventional powders has faced challenges on multicolor surfaces. However, these challenges are addressed by the advent of fluorescent powders in LFP detection, and they have redefined the effectiveness of the powder dusting method. In this study, color-tunable YOF:Tb3+,Eu3+ nanophosphors were examined for LFP recognition and were evaluated for their practicality on different types of surfaces. Under 254 nm UV irradiation, the LFPs developed using these nanophosphors showed clear and distinct ridge patterns with level 1, 2, and 3 details. The ultrafine particles of these nanophosphors adhered to the ridge patterns and replicated the minutiae of the LFPs. Meanwhile, the variation of the Tb3+/Eu3+ ratio demonstrated multicolor fluorescence emission from the nanophosphors, which provided better contrast between the ridge patterns on complex surfaces. Furthermore, the high luminescence quantum yield of the nanophosphors ensured high-resolution fluorescence images of the LFPs with a well-defined pattern that was recognizable even without any microscope or sophisticated instrumentation.

Cation vacancy-boosted BaZnB4O8:xEu3+ phosphors with high quantum yield and thermal stability for pc-WLEDs.

Achieving high luminescent quantum yield and thermal stability of phosphors simultaneously remains challenging, yet it is critical for facilitating high-power white light emitting diodes (WLEDs). Herein, we report the design and preparation of the layered structure BaZnB4O8:xEu3+ (0.10 ≤ x ≤ 0.60) red phosphors with high quantum yield (QY = 76.5%) and thermal stability (82.8%@150 °C) by the traditional solid-state reaction method. The results of XRD and Rietveld refinement show that the presence of Eu3+ ions at Ba2+ sites causes the formation of cation (Zn2+/Ba2+) vacancies in the lattice. The PL and PL decay results reveal that the quenching concentration of BZBO:xEu3+ phosphors is as high as 50%, and the lifetime remains unchanged with Eu3+ concentration due to the unique structure of the host and the cation vacancies generated by the heterovalent substitution. Furthermore, on a 395 nm near-UV chip, a pc-WLED device with exceptional optical performance (CCT = 4415 K, CRI = 92.1) was realized using the prepared BZBO:0.50Eu3+ as a red phosphor. Simple synthesis and excellent performance parameters suggest that the reported BaZnB4O8:xEu3+ phosphors have promising applications in high-power pc-WLEDs. At the same time, it also indicates that cationic vacancy engineering based on heterovalent ion substitution is a potential strategy for improving luminescence quantum yield and thermal quenching performance.

A facile fluorescence imprinted strategy based on boronic acid functionalized MOF and Mg/N-CDs for discrimination of transferrin: Expansion for boronic acid functionalized MOF application

In this research, we proposed a novel fluorescence imprinted sensor (FIS@MIP) for rapid and sensitive detection of transferrin (TrF) based on the boronic acid functionalized Zr-MOF (Zr-UiO-66-B(OH)2) and high fluorescence quantum yield of Mg/N co-doped carbon dots (Mg/N-CDs). The boronic acid moieties of Zr-UiO-66-B(OH)2 could significantly covalently bind TrF and load more Mg/N-CDs to avoid fluorescence quenching caused by self-aggregation of Mg/N-CDs. Additionally, Zr-UiO-66-B(OH)2 was prepared though linker fragmentation approach, which eliminated the complex post modification process and could provide sufficient boric acid groups. High luminescent and fluorescence quantum yield endowed Mg/N-CDs remarkable fluorescence response to TrF. Under the optimal conditions, the fluorescence intensity of FIS@MIP at 438 nm was quenched by Trf within 1 min. Based on specific recognition sites, a good linear relationship was obtained in the linear range of 0.1 µM–20 µM, and the low detection limit was determined as 0.067 µM. In order to explore portable detection application, a home-made device based on smartphone was designed for on-site detection of TrF with a detection limit of 0.38 µM. Significantly, this smartphone platform was successfully applied for detection of TrF in simulated actual samples (i.e., human urine and human serum) with satisfactory results, which provided a new promising strategy for on-site and sensitive discrimination of TrF in actual samples. This research will promote the development of the application of boronic-acid functionalized Zr-MOF in molecularly imprinted sensing of glycoproteins..

Recyclable soft photonic crystal film with overall improved circularly polarized luminescence

Existing circularly polarized luminescence materials can hardly satisfy the requirements of both large luminescence dissymmetry factor and high luminescent quantum yield, which hinders their practical applications. Here, we present a soft photonic crystal film embedded with chiral nanopores that possesses excellent circularly polarized luminescence performance with a high luminescence dissymmetry factor as well as a large luminescent quantum yield when loaded with various luminescent dyes. Benefitting from the retention of chiral nanopores imprinted from a chiral liquid crystal arrangement, the chiral soft photonic crystal film can not only endow dyes with chiral properties, but also effectively avoid severe aggregation of guest dye molecules. More importantly, the soft photonic crystal film can be recycled many times by loading and eluting guest dye molecules while retaining good stability as well as circularly polarized luminescence performance, enabling various applications, including smart windows, multi-color circularly polarized luminescence and anticounterfeiting.

Heterobimetallic lanthanide tetrahedral cages: Synthesis, design and application for potential multimodal imaging contrast agent

The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination chemistry. Benefiting from the unique luminescent and magnetic properties of lanthanide ions, the potential applications of lanthanide-organic cages in biological imaging applications are promising, but only a few corresponding explorations have been reported. Herein, we introduced a series of lanthanide tetrahedral cages, (EunGd4–nL4) (sol)8 (n = 0, 1, 2, 3 and 4, where L = (4,4′,4″-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine, and sol = dimethyl sulfoxide and methanol), with potential applications in biological imaging. Given the good luminescent and magnetic properties of Eu3+ and Gd3+ ions, Eu4L4 and Gd4L4 complexes show a high luminescence quantum yield of 29% in DMSO and large longitudinal relaxivity (r1) of 11.4 (mmol/L)−1/s at 0.5 T in water containing 1 vol% DMSO, respectively. The heterobimetallic Eu–Gd complexes achieve a dual imaging mode by combining luminescent and magnetic centers in one cage. When the Gd:Eu ratio increases from 1:3 to 3:1, the r1 values increases from 5.33 to 8.64 (mmol/L)−1/s, higher than that of commercial contrast agent Gd-DOTA (3.23 (mmol/L)−1/s). Owing to their low toxicity and good cell imaging ability toward ECA 109 cells, the self-assembled Eu–Gd heterobimetallic tetrahedral cages could be potential candidates for the multimodal imaging contrast agent.

Cyclic Voltammetry as an Activation Method of TiO2 Nanotube Arrays for Improvement of Photoelectrochemical Water Splitting Performance

AbstractA facile and eco‐friendly method for activating anodic TiO2 nanotubes (TNTs) by cyclic voltammetry (CV) is proposed, and photoelectrochemical properties of CV‐activated TNTs are compared with those of non‐activated TNTs and of TNTs activated by hydrogen‐thermal reduction. EPR and luminescence studies show that the pristine samples demonstrate rather large content of paramagnetic and luminescing defects, while hydrogenation and CV‐activation lead to the different type of rearrangement of defects. TNTs activated by CV‐Na2SO4 demonstrate significantly improved photocurrent density (2.25 mA cm−2) in comparison with that of the hydrogen treated and pristine ones (0.93 mA cm−2 and 0.31 mA cm−2) under NUV‐irradiation at 0.2 V (RHE). Enhanced photoactivity of Na2SO4‐activated TNTs correlates with higher luminescence quantum yield, lowest paramagnetic defects content and larger decay time of the luminescence. Thus, a decrease in the content of defects is an important factor that reduces the non‐radiative recombination of charge carriers. The activation‐induced redistribution of surface and bulk defects in nanotubes explains the increased photoelectrochemical activity of TiO2‐based anodes. Cyclic voltammetry has been proved to be a reliable method to increase the efficiency of TNTs in PEC water splitting.

Ultrahigh porosity photoluminescent silicon aerocrystals with greater than 50% nanocrystal ensemble quantum yields

Three types of mesoporous silicon flakes were fabricated by anodization in methanoic hydrofluoric acid from the same substrates (heavily doped p-type). Even though anodization current density, rinsing, drying method, and storage condition were the same for all three wafers, the resulting porous silicon (PSi) structures had very different properties. They had very different colors. Two of them showed quite high luminescence quantum yields (QYs), confirmed by very long luminescence lifetimes. The highest QY exceeded 50% for a peak photoluminescence wavelength of ∼750 nm. To date, this QY is the highest obtained for PSi and very importantly for silicon with large mesopores, which is typically not highly efficient (as opposed to silicon with small mesopores and microporous silicon). Large mesopores (>15 nm diameter) facilitate impregnation of various substances into luminescent material, such as metals for plasmonics and drugs for theranostics. The differing luminescent properties were correlated to electrolyte temperature during anodization, and evolution of the electrolyte batch (lowering of active fluoride content and buildup of hexafluorosilicate) used to anodize several wafers, whose effects are often overlooked when mass-producing PSi. Supercritical drying and completion of the slow growth of native oxide passivation in the dark leading to different final partially oxidized PSi structures are also important factors for the high QYs obtained. The highest QY was obtained with the structure having the most isolated Si nanocrystals in an amorphous Si oxide tissue.

New anilido-pyridine boron difluorides with high Stokes shift and intrinsic electrofluorochromism

New boron-locked substituted anilido-pyridines were obtained. The compounds exhibit high Stokes shift (up to 147 nm) and practical luminescence quantum yield (up to 62%), both in solution and in a solid state. The compounds demonstrate reversible electrochemical behavior and intrinsic electrofluorochromism. The possibility to modulate the fluorescence by direct electrochemical repetitive on/off switching was demonstrated by the spectroelectrochemical measurements, opening up prospects for creating fluorescent redox-switches based on these compounds.

Construction of High Quantum Yield Lanthanide Luminescent MOF Platform by In Situ Doping and Its Temperature Sensing Performance.

Lanthanide luminescent MOF materials show excellent luminescent properties. However, obtaining lanthanide luminescent MOFs with high quantum yield is a challenging research. A novel bismuth-based metal-organic framework [Bi(SIP)(DMF)2] was constructed by solvothermal method, utilizing 5-sulfoisophthalic acid monosodium salt (NaH2SIP) and Bi(NO3)3·5H2O. Thereafter, doped MOFs (Ln-Bi-SIP, Ln = Eu, Tb, Sm, Dy, Yb, Nd, Er) with different luminescent properties have been obtained by in situ doping with different lanthanide metal ions, among which Eu-Bi-SIP, Tb-Bi-SIP, Sm-Bi-SIP, and Dy-Bi-SIP have high quantum yield. What is special is that the doping amount of Ln3+ ions is very low, and the doped MOF can achieve high luminescence quantum yields. EuTb-Bi-SIP obtained by Eu3+/Tb3+ codoping and Dy-Bi-SIP exhibit good temperature sensing performance over a wide temperature range with the maximum sensitivity Sr of 1.6%·K-1 (433 K) and 2.6%·K-1, respectively (133 K), while the cycling experiments also show good repeatability in the assay temperature range. Finally, considering the practical application value, EuTb-Bi-SIP was blended with an organic polymer poly(methyl methacrylate) (PMMA) to produce a thin film, which shows different color changes at different temperatures.

Electrooptical switching and photopatterning of luminescence in nematic liquid crystals doped with mesogenic europium complex

Stimuli-responsive self-organized soft matter such as liquid crystals, polymers, gels attracts great attention due to a variety of possible applications in modern technologies. Electroinduced hydrodynamic (EHD) instability in liquid crystals is one of long-discovered effects that shows a great potential for future applications. However, this effect is insufficiently studied and its practical implementation has yet to be found. In the present paper, we applied an EHD instability to tuning luminescent properties of nematic mixtures doped with a highly emissive europium complex, which has good solubility in a liquid crystalline (LC) matrix and high quantum yield of luminescence. Nematic mixtures studied in this work possess negative anisotropy of dielectric constant and positive anisotropy of conductivity that allow for observing convective EHD patterns induced by ionic conductivity. The influence of field frequency on the threshold voltage was studied and optimal conditions for induction of EHD patterns were determined. The luminescence intensity was found to substantially decrease or increase under an applied electric field depending on the alignment behavior of LC molecules inside the cells and the angle of observation. In a tilted cell (60°), the emission intensity gradually increases under applied electric field and reaches values ca. 2.5 times higher than in zero field conditions. This phenomenon is associated with alignment of the europium complex molecules along electric field direction (cooperatively with LC molecules) and EHD-induced light scattering. Kinetics of electrooptic switching was studied and different approaches to luminescence photopatterning of the studied nematic mixture with polymerizable monoacrylate and diacrylate were demonstrated.

Binuclear Lanthanide Complexes Based on 4-Picoline-N-oxide: From Sensitized Luminescence to Single-Molecule Magnet Characteristics

Lanthanide complexes featuring luminescent and/or single-molecule magnet (SMM) characteristic(s) are proposed candidates to develop molecule-based spintronics, memory, and quantum information processing (QIP) device architectures. Herein, we report on the luminescent and/or SMM characteristic(s) of charge-neutral binuclear lanthanide complexes─[Ln2Cl6(4-picNO)4(μ2-4-picNO)2]·2H2O (Ln3+ = Tb3+ ([Tb2]) or Dy3+ ([Dy2]); 4-picNO = 4-picoline-N-oxide). The Dy and Tb complexes show 4-picNO-sensitized luminescence with quantum yields in the solid state of 0.14% and 88%, respectively. The luminescent Dy complex is an SMM with a magnetization reversal barrier (Ueff) = 20.6(4) cm–1 under zero applied magnetic field, whereas the Tb complex is not an SMM. The facile preparation of [Ln2Cl6(4-picNO)4(μ2-4-picNO)2]·2H2O complexes showing high luminescence quantum yield (Tb3+) and SMM characteristics (Dy3+) might prove useful toward the designing of analogue luminescent-SMM hybrids suitable for technological applications.

Fluorescent boron difluoride curcuminoides as perspective materials for bio-visualization

Curcuminoids of boron difluoride, 1-aryl(hetaryl)-5-phenylpenta-2,4-dien-1-onates of boron difluoride, have been synthesized. A comparative study of the electronic structure, luminescent properties and their potential for applications in bio-imaging has been carried out. The influence of the electronic structure of α-substituents on the luminescence of compounds was studied by the methods of stationary and time-resolved luminescence spectroscopy and DFT modeling. The introduction of π-donor substituents leads to a noticeable bathochromic shift and an increase in the Stokes shift in the luminescence spectra. On going from σ-donor substituents in the phenyl ring to π-donor substituents, the luminescence quantum yield increases from 0.03 to 0.22. The maximum Stokes shift and high quantum yield of luminescence is exhibited by the complex with a stilbene substituent, which has the longest π-system and the maximum efficiency of charge transfer. Dyes are able to penetrate into the cells of the model cell line and accumulate, moreover, accumulation occurs mainly in the cytoplasm of cells. The compounds penetrate into the cells by 12 h of incubation without damaging it’s structure and without causing rapid cell death. The submicromolar range of non-toxic concentrations during long-term incubation for a model cell line was determined, which is a characteristic of fluorescent imaging. Due to uniform distribution in the cytoplasm of cells dye with naphtyl substituent is promising for visualization of the cell cytoplasm. This leader compound has the lowest cytotoxicity for cells from the synthesized series of dyes, which makes it promising for further studies as a fluorescent imaging agent.The leader compound has the lowest cytotoxicity for cells from the synthesized series of dyes, which makes it promising for further studies as a fluorescent imaging agent.

Solvent-Type Passivation Strategy Controls Solid-State Self-Quenching-Resistant Behavior in Sulfur Dots.

Treatment of sulfur dots with polyethylene glycol (PEG) has been an efficient way to achieve a high luminescence quantum yield, and such a PEG-related quantum dot (QD)-synthesis strategy has been well documented. However, the polymeric insulating capping layer acting as the "thick shell" will significantly slow down the electron-transfer efficiency and severely hamper its practical application in an optoelectric field. Especially, the employment of synthetic polymers with long alkyl chains or large molecular weights may lead to structural complexity or even unexpected changes of physical characteristics for QDs. Therefore, in sulfur dot preparation, it is a breakthrough to use short-chain molecular species to replace PEG for better control and reproducibility. In this article, a solvent-type passivation (STP) strategy has been reported, and no PEG or any other capping agent is required. The main role of the solvent, ethanol, is to directly react with NaOH, and the generated sodium ethoxide passivates the surface defects. The afforded STP-enhanced emission sulfur dots (STPEE-SDs) possess not only the self-quenching-resistant feature in the solid state but also the extension of fluorescence band toward the wavelength as long as 645 nm. The realization of sulfur dot emission in the deep-red region with a decent yield (8.7%) has never been reported. Moreover, a super large Stokes shift (300 nm, λex = 345 nm, λem = 645 nm) and a much longer decay lifetime (109 μs) have been found, and such values can facilitate to suppress the negative influence from background signals. Density functional theory demonstrates that the surface passivation via sodium ethoxide is dynamically favorable, and the spectroscopic insights into emission behavior could be derived from the passivation effect of the sulfur vacancy as well as the charge-transfer process dominated by the highly electronegative ethoxide layer.

Portable and luminescent fiber based sensing device for antibiotics in human urine and real water samples

A new lanthanide complex is designed and obtained based on the ligand of 2,4,5,6-tetrafluoroisophthalic acid (H2TFPA) and 1,10-phenanthroline (phen) under mild hydro(solvo)thermal conditions. The new complex has the molecular formula of [Tb2(TFBA)3(phen)2(H2O)2]n (TbMOF) and it is characterized in detail. It is confirmed that TbMOF shows high water stability, thermal stability, acid and alkali resistance. The experimental results show that TbMOF solid state sample shows a luminescence decay lifetime of 0.448 ms, and a high luminescence quantum yield (QY) of 38.15%. Interestingly, studies showed that TbMOF is an excellent sensor for detecting antibiotics of ciprofloxacin (CIP). In addition, the limit of detection (LOD) for CIP is an extremely high sensitivity value of 0.17 ppm. In the concentration range of 1.0 × 10−7-1.0 × 10−6 M, CIP shows an excellent linear relationship with the luminescence intensity of TbMOF. Most importantly, test paper based on TbMOF and fiber material of filter paper is fabricated, which is a strongly anti-interference, selective, sensitive, portable and visible to the naked eyes sensing device towards CIP in real samples of human urine, tap water, and lake water.