Luminescence Response Research Articles

A robust turn-on luminescent MOF probe with redox center and rare RE4 cluster for highly sensitive detection of captopril

Sensitive detection of captopril (CP) is necessary from a point of physiological, but the nature of no luminescence response and low ultraviolet absorption make it difficult in luminescent technology. Here, a series of novel RE(III)-MOFs featuring the rare tetranuclear RE4(μ3-OH)2(μ2-COO)8 cluster, namely, {[RE4(tbia)4(NO3)2(OH)2(H2O)4]·CH3CN}n (RE-tbia, RE3+ = Sm3+ (1), Eu3+ (2), Gd3+ (3), Tb3+ (4), Dy3+ (5), Er3+ (6), Yb3+ (7), H2tbia = 5-((4′-(triazol-1-yl)benzyl)oxy)isophthalic acid), have been successfully synthesized via a solvothermal reaction. The as-prepared Tb-tbia shows high water stability, thermal stability and excellent luminescence property through an antenna effect due to the unique RE4 cluster. Considering the sulfhydryl groups in the CP, a redox center Ce(IV) was introduced to construct a stable luminescent probe Ce0.2Tb0.8-tbia for turn-on luminescence detecting CP molecules. The reactive Ce4+ redox centers not only optimize the luminescence intensity of Tb-tbia, but also act as redox centers and react with CP to form captopril-disulfide (CP-DS). Therefore, the Ce0.2Tb0.8-tbia possesses a low detection limit of 64.6 nM for CP in the aqueous solution, showing a high sensitivity and application perspective.

Luminescent β-diketonate coordinated europium(III) sensor for rapid and sensitive detection of Bacillus Anthracis biomarker

The hazardous B. Anthracis are harmful pathogens causes anthrax could be potentially used as biothreat agents or bioweapons and have severe consequences to public health. These bacterial endospores contain dipicolinic acid (DPA) as calcium dipicolinate (CaDPA) as a primary cell wall constituent (1 M, 1015 molecules/spore). The anthrax attacks in USA by shipping spores in postal mails have triggered the hunt for a simple, rapid, sensitive, and selective detection of Bacillus Anthracis spores. Therefore, a fast and sensitive sensing platform for anthrax spores is critical to contain such biothreats and outbreaks of infection. Herein, we intend to develop a sensitive and selective optical detection strategy for anthrax spore biomarker based on DPA-sensitized lanthanide luminescence. The anionic hard DPA2− strongly binds with hard Ln3+ forming thermodynamically stable complex and sensitizing unique LnIII time-resolved luminescence originated from f-f transitions with a high S/N ratio. Here, we employed and repurposed a simple luminescent EuIII complex: [Eu(TTA)3(H2O)2] (1) (TTA: 3-thenoyltrifluoroacetonate) for the detection of the DPA2− biomarker. Complex 1, when titrated with DPA, displayed instant Switch-ON optical response by 10-fold enhancement in the time-resolved luminescence (TRL) intensity of the 5D0→7F2 transition, which is sensitive to the changes in the symmetry of the EuIII primary coordination sphere. Upon binding with DPA, we also observed shifting of the excitation wavelength (λex) from ∼345 nm to 275 nm in the presence of ∼3.0 mol equivalent of dipicolinic acid. After stoichiometric reaction with DPA, the resulting complex has a long-lived, highly stable excited state of the EuIII ion with a lifetime of 2100 μs in solution compared to only 260 μs for the original probe. We proposed possible displacement of the TTA− and H2O from the primary coordination sphere of the EuIII ion by potent chelating antenna ligand DPA2−. This reaction results in the formation of nine-coordinated [Eu(DPA)3]3- complex in solution confirmed by ESI-MS analysis. The luminescence response of the complex 1 is found highly selective for DPA in the presence of various interfering carboxylic acids and quantitatively able to detect up to 1.20 μM.

Contact electrification induced mechanoluminescence

Mechanoluminescence (ML) is a luminescence response to mechanical stimuli that shows a variety of significant applications. It is generally believed that ML is due to piezoluminescence in asymmetric piezoelectric materials, but this model encounters difficulties in explaining the ML for centrosymmetric nonpiezoelectric materials, especially the Lu3Al5O12: Ce3+/PDMS elastomer with ultrastrong nonpreirradiation ML. This theoretical problem has become the prominent “dark cloud” in the sky of the ML field. This work reveals for the first time that the ML for the centrosymmetric Lu3Al5O12: Ce3+/PDMS elastomer is essentially induced by contact electrification. According to contact electrification, an electron-cloud model of contact electrification is successfully established to understand the ML mechanism for the elastomer. This demonstrates that contact electrification arising from the interaction of two dissimilar surfaces creates a broadband excitation energy, which directly excites the luminescence levels to emit ML. Accordingly, the unique ML properties of the centrosymmetric Lu3Al5O12: Ce3+/PDMS elastomer that cannot be explained by piezoelectricity can be well understood by contact electrification. Particularly, these results also inspire us to have reasonable new insight into the trap-dependent piezoluminescence mechanism for typical SrAl2O4: Eu2+ and ZnS: Cu/Mn2+ materials.

Regulatable Detection of Antibiotics Based on a Near-IR-Luminescent Tubelike Zn(II)-Yb(III) Nanocluster.

A tubelike Zn(II)-Yb(III) cluster, [Zn6Yb5L5(HL)(NO3)4(DMF)6(EtOH)4(H2O)4] (1; DMF = N,N-dimethylformamide and EtOH = ethanol; molecular size 1.5 × 1.8 × 2.9 nm), was synthesized from a new long-chain Schiff base ligand. 1 exhibits a regulatable near-IR-luminescent response to nitrofuran antibiotics (NFAs) and fluoroquinolones with high sensitivity, which is not influenced by other antibiotics. The quenching constants of NFAs and fluoroquinolones range from 0.55 × 104 to 8.8 × 104 M-1, and the detection limits of 1 to them are from 4.2 × 10-4 to 2.6 × 10-5 M. It also shows a luminescent response to real antibiotic drugs containing NFAs and fluoroquinolones.

Geometrical effects on luminescent dosimeter energy response

Luminescent dosimeters are widely used in medical applications. For an optimal use of these dosimeters, comparative studies of their characteristics, under clinical radiations, are very useful. The purpose of this study is to establish the effect of dosimeter geometry on the luminescent dosimeter energy response for different clinical radiation beams. Monte Carlo simulations were used to calculate the energy response of three kinds of non-commercialized luminescent dosimeters. The dosimeters are: a) radiophotoluminescent glass dosimeter (RPLGD, typeFD-7 glass), b) thermoluminescent dosimeter (TLD, type LiF:Mg,Ti) and c) optically stimulated dosimeter (OSLD, type Al2O3:C).The studied dosimeters have cylindrical geometry with a thickness of 2mm and diameters ranging from 1 to 13 mm. The radiation beams were 70 kV X-ray beam, clinical photon beam of 15 MV and clinical electron beam of 9 MeV. This study confirms a non-negligible effect on the dosimeter geometry on its energy response for these beams.

Photo- and radio-luminescence of porphyrin functionalized ZnO/SiO2 nanoparticles.

The development of hybrid nanoscintillators is hunted for the implementation of modern detection technologies, like in high energy physics, homeland security, radioactive gas sensing, and medical imaging, as well as of the established therapies in radiation oncology, such as in X-ray activated photodynamic therapy. Engineering of the physico-chemical properties of nanoparticles (NPs) enables the manufacture of hybrids in which the conjugation of inorganic/organic components leads to increased multifunctionality and performance. However, the optimization of the properties of nanoparticles in combination with the use of ionizing radiation is not trivial: a complete knowledge on the structure, composition, physico-chemical features, and scintillation property relationships in hybrid nanomaterials is pivotal for any applications exploiting X-rays. In this paper, the design of hybrid nanoscintillators based on ZnO grown onto porous SiO2 substrates (ZnO/SiO2) has been performed in the view to create nanosystems potentially suitable in X-ray activated photodynamic therapy. Indeed, cytotoxic porphyrin dyes with increasing concentrations have been anchored on ZnO/SiO2 nanoparticles through amino-silane moieties. Chemical and structural analyses correlated with photoluminescence reveal that radiative energy transfer between ZnO and porphyrins is the principal mechanism prompting the excitation of photosensitizers. The use of soft X-ray excitation results in a further sensitization of the porphyrin emission, due to augmented energy deposition promoted by ZnO in the surroundings of the chemically bound porphyrin. This finding unveils the cruciality of the design of hybrid nanoparticles in ruling the efficacy of the interaction between ionizing radiation and inorganic/organic moieties, and thus of the final nanomaterial performances towards the foreseen application.

Multi analyte sensing of amphiphilic tridentate bis(benzimidazolyl)pyridine incorporated in liposomes and potential application in enzyme assay.

A liposome based nanosensor Lipo-1 for efficient detection of copper, cyanide (CN-) and ATP in a pure aqueous medium has been described. Lipo-1 shows a fluorescence ON-OFF response with copper. However, Lipo-1.Cu (Lipo-1 and copper ensemble) was used for the OFF-ON detection of ATP with nM and CN- with μM detection levels, lower than the WHO permissible level for safe drinking. Lipo-1 has better and enhanced binding properties over the counter organic amphiphilic compound Bzimpy-LC, which is not soluble in water. The significant changes in the emission spectra in the presence of Cu2+, CN- and ATP ions, as variable inputs, are used to construct INHIBIT and OR logic operations in a nano-scale environment. The fluorescent detection of CN- ions with Lipo-1.Cu was used to develop an enzyme assay for β-glucosidase using amygdalin as the substrate. β-Glucosidase enzymatic activity was monitored by the emission OFF-ON signal of the probe Lipo-1.Cu by CN- detection. This approach could be an efficient method for developing a fluorescence-based β-glucosidase enzyme assay. A switch ON luminescence response, low detection limit, fast response, 100% aqueous solution, biocompatibility, multi-analyte detection, and improved sensitivity and selectivity of Bzimpy-LC in lipid bilayer membranes are the main features of the nanoprobe Lipo-1. These properties give it a clear advantage for analytical applications.

A Schiff Base with Excited-State Intramolecular Proton Transfer and its Zinc(Ii) Complex: Mechanochromic Luminescence and Acid-Base Stimuli Response

A Schiff Base with Excited-State Intramolecular Proton Transfer and its Zinc(Ii) Complex: Mechanochromic Luminescence and Acid-Base Stimuli Response

Achieving circularly polarized luminescence and large piezoelectric response in hybrid rare-earth double perovskite by a chirality induction strategy.

Chirality, an intrinsic property of nature, has received increased attention in chemistry, biology, and materials science because it can induce optical rotation, ferroelectricity, nonlinear optical response, and other unique properties. Here, by introducing chirality into hybrid rare-earth double perovskites (HREDPs), we successfully designed and synthesized a pair of enantiomeric three-dimensional (3D) HREDPs, [(R)-N-methyl-3-hydroxylquinuclidinium]2RbEu(NO3)6 (R1) and [(S)-N-methyl-3-hydroxylquinuclidinium]2RbEu(NO3)6 (S1), which possess ferroelasticity, multiaxial ferroelectricity, high quantum yields (84.71% and 83.55%, respectively), and long fluorescence lifetimes (5.404 and 5.256 ms, respectively). Notably, the introduction of chirality induces the coupling of multiaxial ferroelectricity and ferroelasticity, which brings about a satisfactory large piezoelectric response (103 and 101 pC N-1 for R1 and S1, respectively). Moreover, in combination with the chirality and outstanding photoluminescence properties, circularly polarized luminescence (CPL) was first realized in HREDPs. This work sheds light on the design strategy of molecule-based materials with a large piezoelectric response and excellent CPL activity, and will inspire researchers to further explore the role of chirality in the construction of novel multifunctional materials.

A europium(iii)-based nanooptode for bicarbonate sensing – a multicomponent approach to sensor materials

Lanthanide luminescence contains detailed chemical information and can be used to report on several chemical analytes. This has been exploited through elaborate synthesis of responsive lanthanide complexes. Here, we report on a less elaborate approach and assemble four different nanooptodes. Europium(III) is used to sense the bicarbonate concentration. The signal from the optode was enhanced 100 times using antenna chromophore and the response was modulated by the addition of lipophilic cations.

Efficient photoswitchable organometallic complexes with azobenzene and stilbene units: the case of Au(i)

Mononuclear Au(i) complexes with ligands containing azobenzene or stilbene demonstrate efficient trans → cis photoisomerization and luminescent response of the “on–off” process.

Monitoring of the yogurt fermentation process based on a rapid bio-luminescent chiral pattern recognition of amino acids.

The analysis of chiral α-amino acids is of great significance in asymmetric synthesis, nutrition, food science, and microbiology. However, the ability of chiral recognition is difficult to achieve. Due to the demand for expensive equipment and skilled operators, traditional methods such as high-performance liquid chromatography are limited. The previously reported methods based on chemical sensor arrays usually cannot carry out the chiral analysis. Here, we developed a novel biosensor array based on the interaction between a suite of host-based luminescent bacteria and amino acids and used linear discriminant analysis to reflect their luminescence response patterns. This biosensor array could effectively discriminate chiral amino acids, including 19 L-amino acids, their corresponding D-enantiomers, and the achiral glycine. In addition, the determination of enantiomeric purity and quantitative ability has been proved. The successful identification of a complex system containing multiple chiral amino acids further demonstrates the superiority of the bioluminescent sensor array. Moreover, this sensor array could efficiently monitor the dynamic composition of free amino acids in the process of milk fermentation. Finally, the bioluminescence response mechanism of the luminescent bacteria for the recognition of chirality was clarified. This approach possessed the advantages of facile construction, high throughput, easy operation, high accuracy and fast response.

Construction of a Cd8Tb4 nanoring for luminescence response to 2,6-dipicolinic acid as an anthrax biomarker

One 12-metal Cd(ii)–Tb(iii) nanoring (1.2 × 2.8 × 2.8 nm) was constructed from a flexible Schiff base ligand, and it shows luminescent response to 2,6-dipicolinic acid with high sensitivity and selectivity.

Determination of Hydroxychloroquine by Cathodic Electrochemiluminescence.

Cathodic electrochemiluminescence (CECL) of hydroxychloroquine (HCQ) in aqueous solutions on an aluminum electrode is described. The analytical possibilities of the phenomenon are evaluated. The conditions for HCQ determination in slightly alkaline and acidic solutions are optimized. The possibility of analysis in the concentration range 0.1 – 300 mg/L is shown. CECL can be a supplement to well-known methods of HCQ determination in pharmaceuticals by a method based on a new type of luminescent response signal.

Optical sensing of aqueous nitrate anion by a platinum(II) triimine salt based solid state material.

Selective and quantitative measurement of aqueous nitrate (NO3-) anion is achieved using solid [Pt(Cl-4-tpy)Cl]ClO4 salt (Cl-4-tpy = 4-chloro-2,2':6'2''-terpyridine), and as the salt supported on controlled porous glass. This detection method relies on the color change of the Pt(II) complex from yellow to red and intense luminescence response upon ClO4- exchange with NO3- due to concomitant enhancement of Pt⋯Pt interactions. The spectroscopic response is highly selective for NO3- over a large range of halides and oxoanions.

Formaldehyde recognition through aminal formation in a luminescent metal-organic framework.

Two isostructural pillar-layer MOFs (JNU-105 and JNU-105-(NH2)2) have been successfully synthesized. JNU-105-(NH2)2 exhibits a red-shifted luminescence "turn on" for formaldehyde without the interference from other VOCs and a detection limit of 1.87 ppb. In situ single-crystal transformation studies confirm the aminal formation on the pillar linker, which was attributed to the exclusive luminescence response toward formaldehyde.

Epitaxial coordination assembly of a semi-conductive silver-chalcogenide layer-based MOF.

Using a carboxylic acid linker, this work achieved the epitaxially coordinated assembly of a Ag-S layer into a three-dimensional semi-conductive framework, with high thermal stability, as well as an interesting temperature-dependent luminescence response. This work provides a new avenue to prepare semi-conductive metal-chalcogenide layer-based materials in electricity-related applications.

Механизм люминесцентного хемосенсорного отклика в хелатах европия(III)

There were studied the luminescent chemosensory properties of Eu(III) carboxylatodibenzoylmethanates with acetic and acrylic acids while the interaction with ammonia vapors. Quantitative measurements of the optical response showed that with an increase in the analyte concentration in the range of 3-330 ppm, a linear increase in the luminescence intensity of europium(III) is observed. The reversibility of the luminescent response was established, the limit of detection of ammonia was 3 ppm. The mechanism of the optical effect is revealed by the method of quantum chemical modeling: the interaction of ammonia with the sensor leads to the formation of a rigid structural fragment of H2O–NH3, which blocks the quenching effect of high-frequency OH vibrations on luminescence. The studied chemosensors have high sensitivity and selectivity and, thus, can be promising for creating ammonia detection sensors for food safety control and environmental monitoring.

PH dependent sensitization of europium in a hydrogen bonded three-dimensional metal–organic compound with (4966)2(4462)3 topology: luminescence titration and time-resolved studies

A europium-doped MOC shows interesting metal and ligand-centered luminescence response from pH 2 to 11.

A new three-dimensional zinc(II) metal-organic framework as a fluorescence sensor for sensing the biomarker 3-nitrotyrosine.

3-Nitrotyrosine (3-NT), an oxidative stress biomarker, is closely associated with various diseases. Thus, rapid and sensitive detection of 3-NT is of great significance for preventing and treating diseases. Herein, we reported a new 3D zinc-based metal-organic framework (Zn-MOF) [Zn(L)(HBTC)] (L = (E)-4,4'-(ethene-1,2-diyl)bis[(N-pyridin-3-yl)benzamide], H3BTC = 1,3,5-benzenetricarboxylic acid), which was structurally characterized by single crystal X-ray diffraction, IR, PXRD and TG. The Zn-MOF can be used as a highly efficient fluorescence sensing material to provide a direct and low-cost method for the rapid detection of 3-NT and shows high sensitivity with a KSV value of 6.596 × 104 M-1, a rapid luminescence response within 24 s, excellent selectivity, high anti-interference ability and good recyclability. It is the first example of a MOF being used to directly detect 3-NT as a luminescence sensor to our knowledge. The sensing mechanism of the Zn-MOF towards 3-NT is discussed in detail, which provides a basis for the rational design of MOF sensing materials and their application in biomarker detection.