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1.
Light Sci Appl ; 8: 84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31645928

RESUMO

Machine learning has provided a huge wave of innovation in multiple fields, including computer vision, medical diagnosis, life sciences, molecular design, and instrumental development. This perspective focuses on the implementation of machine learning in dealing with light-matter interaction, which governs those fields involving materials discovery, optical characterizations, and photonics technologies. We highlight the role of machine learning in accelerating technology development and boosting scientific innovation in the aforementioned aspects. We provide future directions for advanced computing techniques via multidisciplinary efforts that can help to transform optical materials into imaging probes, information carriers and photonics devices.

2.
Nat Commun ; 9(1): 3462, 2018 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-30150637

RESUMO

All-inorganic CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (PeQDs) have shown great promise in optoelectronics and photovoltaics owing to their outstanding linear optical properties; however, nonlinear upconversion is limited by the small cross-section of multiphoton absorption, necessitating high power density excitation. Herein, we report a convenient and versatile strategy to fine tuning the upconversion luminescence in CsPbX3 PeQDs through sensitization by lanthanide-doped nanoparticles. Full-color emission with wavelengths beyond the availability of lanthanides is achieved through tailoring of the PeQDs bandgap, in parallel with the inherent high conversion efficiency of energy transfer upconversion under low power density excitation. Importantly, the luminescent lifetimes of the excitons can be enormously lengthened from the intrinsic nanosecond scale to milliseconds depending on the lifetimes of lanthanide ions. These findings provide a general approach to stimulate photon upconversion in PeQDs, thereby opening up a new avenue for exploring novel and versatile applications of PeQDs.

3.
Small ; 14(40): e1801882, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30066496

RESUMO

Half a century after its initial emergence, lanthanide photonics is facing a profound remodeling induced by the upsurge of nanomaterials. Lanthanide-doped nanomaterials hold promise for bioapplications and photonic devices because they ally the unmatched advantages of lanthanide photophysical properties with those arising from large surface-to-volume ratios and quantum confinement that are typical of nanoobjects. Cutting-edge technologies and devices have recently arisen from this association and are in turn promoting nanophotonic materials as essential tools for a deeper understanding of biological mechanisms and related medical diagnosis and therapy, and as crucial building blocks for next-generation photonic devices. Here, the recent progress in the development of nanomaterials, nanotechnologies, and nanodevices for clinical uses and commercial exploitation is reviewed. The candidate nanomaterials with mature synthesis protocols and compelling optical uniqueness are surveyed. The specific fields that are directly driven by lanthanide doped nanomaterials are emphasized, spanning from in vivo imaging and theranostics, micro-/nanoscopic techniques, point-of-care medical testing, forensic fingerprints detection, to micro-LED devices.

4.
Nat Nanotechnol ; 13(10): 879-880, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30082924
5.
J Med Chem ; 60(21): 8923-8932, 2017 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-28991460

RESUMO

A unique, dual-function, photoactivatable anticancer prodrug, RuEuL, has been tailored that features a ruthenium(II) complex linked to a cyclen-europium chelate via a π-conjugated bridge. Under irradiation at 488 nm, the dark-inactive prodrug undergoes photodissociation, releasing the DNA-damaging ruthenium species. Under evaluation-window irradiation (λirr = one-photon 350 nm or two-photon 700 nm), the drug delivery process can be quantitatively monitored in real-time because of the long-lived red europium emission. Linear relationships between released drug concentration and ESI-MS or luminescence responses are established. Finally, the efficiency of the new prodrug is demonstrated both in vitro RuEuL anticancer prodrug over some existing ones and open the way for decisive improvements in multipurpose prodrugs.


Assuntos
Antineoplásicos/química , Európio/química , Pró-Fármacos/química , Rutênio/química , Animais , Liberação Controlada de Fármacos/efeitos da radiação , Monitoramento de Medicamentos/métodos , Humanos , Luz , Fotólise , Pró-Fármacos/efeitos da radiação , Análise Espectral
6.
Inorg Chem ; 54(18): 9166-73, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26340341

RESUMO

Homoleptic mononuclear nine-coordinate lanthanum(III) and europium(III) tris-complexes [Ln(N(∧)N(∧)O)3]·nH2O with two tridentate N-benzylbenzimidazole pyridine-2-carboxylates exhibit a rare C3-symmetry of the lanthanide coordination polyhedron in the solid state, as confirmed by luminescence spectroscopy and by X-ray crystallography (the three N(∧)N(∧)O ligands are arranged "up-up-up" around the lanthanide ion). The symmetry, however, is changed to the more common C1 upon dissolution of the complexes in dichloromethane, as revealed by luminescence spectroscopy (the three ligands are likely to be arranged "up-up-down"). The new europium complexes emit efficient ligand-sensitized metal-centered luminescence with excited-state lifetimes of 1.56-2.18 ms and quantum yields of 25-41% in the solid and in solution. The change of the symmetry from (a higher) C3 to (a lower) C1 alters the luminescence spectrum, shortens the radiative lifetime, and increases the luminescence efficiency of the europium complexes.

7.
Inorg Chem ; 53(16): 8407-17, 2014 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-25068684

RESUMO

Reaction of Ln(III) with a tetrakis(diketone) ligand H4L [1,1'-(4,4'-(2,2-bis((4-(4,4,4-trifluoro-3-oxobutanoyl) phenoxy)methyl)propane-1,3-diyl)bis(oxy)bis(4,1-phenylene))bis(4,4,4-trifluorobutane-1,3-dione)] gives new podates which, according to mass spectral data and Sparkle/AM1 calculations, can be described as dimers, (NBu4[LnL])2 (Ln = Eu, Tb, Gd:Eu), in both solid-state and dimethylformamide (DMF) solution. The photophysical properties of the Eu(III) podate are compared with those of the mononuclear diketonate (NBu4[Eu(BTFA)4], BTFA = benzoyltrifluoroacetonate), the crystal structure of which is also reported. The new Eu(III) dimeric complex displays bright red luminescence upon irradiation at the ligand-centered band in the range of 250-400 nm, irrespective of the medium. The emission quantum yields and the luminescence lifetimes of (NBu4[EuL])2 (solid state: 51% ± 8% and 710 ± 2 µs; DMF: 31% ± 5% and 717 ± 1 µs) at room temperature are comparable to those obtained for NBu4[Eu(BTFA)4] (solid state: 60 ± 9% and 730 ± 5 µs; DMF: 30 ± 5% and 636 ± 1 µs). Sparkle/AM1 calculations were utilized for predicting the ground-state geometries of the Eu(III) dimer. Theoretical Judd-Ofelt and photoluminescence parameters, including quantum yields, predicted from this model are in good agreement with the experimental values, proving the efficiency of this theoretical approach implemented in the LUMPAC software (http://lumpac.pro.br). The kinetic scheme for modeling energy transfer processes show that the main donor state is the ligand triplet state and that energy transfer occurs on both the (5)D1 (44.2%) and (5)D0 (55.8%) levels. Furthermore, the newly obtained Eu(III) complex was doped into a PMMA matrix to form highly luminescent films and one-dimensional nanowires having emission quantum yield as high as 67%-69% (doping concentration = 4% by weight); these materials display bright red luminescence even under sunlight, so that interesting photonic applications can be foreseen.

8.
Inorg Chem ; 53(10): 5171-8, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24807159

RESUMO

We report on new anionic tridentate benzimidazole-pyridine-tetrazolate ligands that form neutral 3:1 complexes with trivalent lanthanides. The ligands are UV-absorbing chromophores that sensitize the red luminescence of europium with energy-transfer efficiency of 74-100%. The lifetime and quantum yield of the sensitized europium luminescence increase from 0.5 ms and 12-13% for the as-prepared solids to 2.8 ms and 41% for dichloromethane solution. From analysis of the data, the as-prepared solids can be described as aqua-complexes [Ln(κ(3)-ligand)2(κ(1)-ligand)(H2O)x] where the coordinated water molecules are responsible for the strong quenching of the europium luminescence. In solution, the coordinated water molecules are replaced by the nitrogen atoms of the κ(1)-ligand to give anhydrous complexes [Ln(κ(3)-ligand)3] that exhibit efficient europium luminescence. X-ray structures of the anhydrous complexes confirm that the lanthanide ion (La(III), Eu(III)) is nine-coordinate in a distorted tricapped trigonal prismatic environment and that coordination of the lanthanide ion by tetrazolate is weaker than by carboxylate.


Assuntos
Benzimidazóis/química , Európio/química , Luminescência , Compostos Organometálicos/química , Piridinas/química , Tetrazóis/química , Ligantes , Estrutura Molecular , Compostos Organometálicos/síntese química
9.
Philos Trans A Math Phys Eng Sci ; 371(1995): 20120295, 2013 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-23776298

RESUMO

Lanthanide bioprobes and bioconjugates are ideal luminescent stains in view of their low propensity to photobleaching, sharp emission lines and long excited state lifetimes permitting time-resolved detection for enhanced sensitivity. In this paper, we expand our previous work which demonstrated that self-assembled dinuclear triple-stranded helicates [Ln2(L(C2X))3] behave as excellent cell and tissue labels in immunocytochemical and immunohistochemical assays. The synthetic strategy of the hexadentate ditopic ligands incorporating dipicolinic acid, benzimidazole units and polyoxyethylene pendants is revisited in order to provide a more straightforward route and to give access to further functionalization of the polyoxyethylene arms by incorporating a terminal function X. Formation of the helicates [Ln2(L(C2X))3] (X=COOH, CH2OH, COEt, NH2, phthalimide) is ascertained by several experimental techniques and their stability tested against diethylenetriaminepentaacetate. Their photophysical properties (quantum yield, lifetime, radiative lifetime and sensitization efficiency) are presented and compared with those of the parent helicates [Ln2(L(C2))3]. Finally, the cellular uptake of five Eu(III) helicates is monitored by time-resolved luminescence microscopy and their localization in HeLa cells established by co-staining experiments.


Assuntos
Elementos da Série dos Lantanídeos/farmacocinética , Medições Luminescentes/métodos , Técnicas de Sonda Molecular , Frações Subcelulares/metabolismo , Células HeLa , Humanos , Elementos da Série dos Lantanídeos/síntese química , Sondas Moleculares/síntese química , Sondas Moleculares/farmacocinética
10.
Interface Focus ; 3(5): 20130032, 2013 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-24511387

RESUMO

Lanthanide bioprobes and bioconjugates are ideal luminescent stains in view of their low propensity to photobleaching, sharp emission lines and long excited state lifetimes permitting time-resolved detection for enhanced sensitivity. We show here how the interplay between physical, chemical and biochemical properties allied to microfluidics engineering leads to self-assembled dinuclear lanthanide luminescent probes illuminating live cells and selectively detecting biomarkers expressed by cancerous human breast cells.

12.
Front Chem ; 1: 15, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24790943

RESUMO

Two new tridentate(NNO)-bidentate(NN) compartmental ligands, HL(5) and HL(6), are synthesized from pyridine and benzimidazole synthons. They react in aqueous solution under physiological conditions with Zn(II), Ln(III), or a mixture thereof, to yield complexes of different stoichiometries, 1:3, 2:2, 2:3, 1:1:3, the speciation of which is established by UV-visible titrations and ESI mass spectrometry. Photophysical studies of the Eu(III)-containing solutions in Tris-HCl 0.1 M (pH = 7.4) show that lanthanide luminescence arises from a unique N6O3 coordination site with pseudo D 3 symmetry. Relevant parameters such as crystal field splitting, lifetime, radiative lifetime, and intrinsic quantum yield perfectly match those reported for dinuclear 4f-4f helicates in which the Eu(III) ion has the same coordination environment.

13.
J Am Chem Soc ; 134(30): 12675-84, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22725838

RESUMO

This work illustrates a simple approach for optimizing long-lived near-infrared lanthanide-centered luminescence using trivalent chromium chromophores as sensitizers. Reactions of the segmental ligand L2 with stoichiometric amounts of M(CF(3)SO(3))(2) (M = Cr, Zn) and Ln(CF(3)SO(3))(3) (Ln = Nd, Er, Yb) under aerobic conditions quantitatively yield the D(3)-symmetrical trinuclear [MLnM(L2)(3)](CF(3)SO(3))(n) complexes (M = Zn, n = 7; M = Cr, n = 9), in which the central lanthanide activator is sandwiched between the two transition metal cations. Visible or NIR irradiation of the peripheral Cr(III) chromophores in [CrLnCr(L2)(3)](9+) induces rate-limiting intramolecular intermetallic Cr→Ln energy transfer processes (Ln = Nd, Er, Yb), which eventually produces lanthanide-centered near-infrared (NIR) or IR emission with apparent lifetimes within the millisecond range. As compared to the parent dinuclear complexes [CrLn(L1)(3)](6+), the connection of a second strong-field [CrN(6)] sensitizer in [CrLnCr(L2)(3)](9+) significantly enhances the emission intensity without perturbing the kinetic regime. This work opens novel exciting photophysical perspectives via the buildup of non-negligible population densities for the long-lived doubly excited state [Cr*LnCr*(L2)(3)](9+) under reasonable pumping powers.


Assuntos
Cromo/química , Complexos de Coordenação/química , Elementos da Série dos Lantanídeos/química , Substâncias Luminescentes/química , Complexos de Coordenação/síntese química , Transferência de Energia , Elementos da Série dos Lantanídeos/síntese química , Luz , Luminescência , Substâncias Luminescentes/síntese química , Modelos Moleculares , Espectroscopia de Luz Próxima ao Infravermelho
14.
Inorg Chem ; 50(11): 4987-99, 2011 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21553848

RESUMO

Two europium complexes with bis(bipyridine) azamacrocyclic ligands featuring pendant arms with or without π-conjugated donor groups are synthesized and fully characterized by theoretical calculations and NMR spectroscopy. Their photophysical properties, including two-photon absorption, are investigated in water and in various organic solvents. The nonfunctionalized ligand gives highly water-stable europium complexes featuring bright luminescence properties but poor two-photon absorption cross sections. On the other hand, the europium complex with an extended conjugated antenna ligand presents a two-photon absorption cross section of 45 GM at 720 nm but is poorly luminescent in water. A detailed solvent-dependent photophysical study indicates that this luminescence quenching is not due to the direct coordination of O-H vibrators to the metal center but to the increase of nonradiative processes in a protic solvent induced by an internal isomerization equilibrium.


Assuntos
Compostos Aza/química , Európio/química , Compostos Macrocíclicos/química , Compostos Organometálicos/química , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Processos Fotoquímicos , Estereoisomerismo
15.
Inorg Chem ; 50(11): 5137-44, 2011 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21545174

RESUMO

Lanthanide hexafluoroacetylacetonate ternary complexes with 2,2'-bipyridine-N,N'-dioxide, [Ln(hfa)(3)(bpyO2)], were synthesized for Ln = Eu, Gd, Tb, and Lu and fully characterized by elemental, thermal, and mass-spectrometric analyses. The X-ray crystal structure of [Eu(hfa)(3)(bpyO2)]·0.5C(6)H(6) reveals an octa-coordinate metal ion lying in a severely distorted trigonal dodecahedron geometry; the Eu-O distances lie in the range 2.36-2.44 Å with no significant difference between hfa(-) and bpyO2. A detailed comparative photophysical investigation has been carried out to determine the exact influence of the introduction of bpyO2 in the inner coordination sphere of the metal ion in replacement of the two water molecules in [Ln(hfa)(3)(H(2)O)(2)]. While this replacement is detrimental for Tb, it leads to a 15-fold increase in the overall quantum yield for Eu. This large improvement originates from (i) a better sensitization efficiency, the ancillary ligand being responsible for 3/4 of the energy transfer, (ii) elimination of nonradiative deactivation pathways through harmonics of O-H vibrations, and (iii) reduction in the radiative lifetime. The latter influence is rarely documented, but it accounts here for a ≈25% increase in the intrinsic quantum yield, so that more attention should be given to this parameter when designing highly luminescent lanthanide complexes.

17.
Inorg Chem ; 49(20): 9300-11, 2010 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-20849088

RESUMO

The reaction of hydrated lanthanide hexafluoroacetylacetonates, [Ln(hfa)(3)(H(2)O)(2)], with 1,4-disubstituted benzenes afforded a new series of one-dimensional coordination polymers [Ln(hfa)(3)(Q)](∞), where Ln = Eu, Gd, Tb, and Lu and Q = 1,4-diacetylbenzene (acbz), 1,4-diacetoxybenzene (acetbz), or 1,4-dimethyltherephtalate (dmtph). X-ray single crystal analyses reveal [Ln(hfa)(3)(acbz)](∞) (Ln = Eu, Gd, Tb) consisting of zigzag polymeric chains with Ln-Ln-Ln angles equal to 128°, while the arrays are more linear in [Eu(hfa)(3)(acetbz)](∞) and [Eu(hfa)(3)(dmtph)](∞), with Ln-Ln-Ln angles of 165° and 180°, respectively. In all structures, Ln(III) ions are 8-coordinate and lie in distorted square-antiprismatic environments. The coordination polymers are thermally stable up to 180-210 °C under a nitrogen atmosphere. Their volatility has been tested in vacuum sublimation experiments at 200-250 °C and 10(-2) Torr: the metal-organic frameworks with acetbz and dmtph can be quantitatively sublimed, while [Ln(hfa)(3)(acbz)](∞) undergoes thermal decomposition. The triplet state energies of the ancillary ligands, 21,600 (acetbz), 22,840 (acbz), and 24,500 (dmtph) cm(-1), lie in an ideal range for sensitizing the luminescence of Eu(III) and/or Tb(III). As a result, all of the [Ln(hfa)(3)(Q)](∞) polymers display bright red or green luminescence due to the characteristic (5)D(0) → (7)F(J) (J = 0-4) or (5)D(4) → (7)F(J) (J = 6-0) transitions, respectively. Absolute quantum yields reach 51(Eu) and 56(Tb) % for the frameworks built from dmtph. Thin films of [Eu(hfa)(3)(Q)](∞) with 100-170 nm thickness can be obtained by thermal evaporation (P < 3 × 10(-5) Torr, 200-250 °C). They are stable over a long period of time, and their photophysical parameters are similar to those of the bulk samples so that their use as active materials in luminescent devices can be envisaged. Mixtures of [Ln(hfa)(3)(dmpth)](∞) with Ln = Eu and Tb yield color-tunable microcrystalline materials from red to green. Finally, the crystalline samples exhibit strong triboluminescence, which could be useful in the design of pressure and/or damage detection probes.

18.
Inorg Chem ; 49(10): 4657-64, 2010 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-20392073

RESUMO

A series of six tetradentate polypyridine-type ligands (L) have been used to prepare the corresponding Eu(III) complexes [Eu(L)(2)(S)](n+) (n = 2, 3) where S = H(2)O or CF(3)SO(3)(-). Two of the ligands, 2,9-di(pyrid-2'-yl)-1,10-phenanthroline (4) and its dipyridophenazine analogue (6) are symmetrical around a central phenanthroline ring. The other four ligands are 2,2'-bi-1,10-phenanthroline and its 3,3'-di-, tri-, and tetramethylene-bridged analogues (5a-d) whose conformations are governed by the length of the polymethylene bridge. (1)H NMR and X-ray analysis indicate that all of the complexes have a C(2v) symmetry. The biphenanthroline series shows a strong correlation of the conjugation between the two halves of the ligand, as governed by the bridge, with the absorption and emission properties of the Eu(III) complex. The complex having the most distorted, tetramethylene-bridged ligand exhibits a weak, high energy pi-pi* absorption and low sensitization efficiency. The luminescence decays are monoexponential for complexes of 4 and either monoexponential or biexponential for the complexes of 5 depending on its solution concentration and the length of the bridge. The complexes of 4 exhibit much longer lifetime, higher overall quantum yield, and higher sensitization efficiency than complexes of 5 while the complex of 6 emits very weakly. The Eu((5)D(0)) lifetime for [Eu(4)(2)(H(2)O)](ClO(4))(3) is shorter than for [Eu(4)(2)(CF(3)SO(3))](CF(3)SO(3))(2), reflecting the effect of the coordinated water. The complexes are examined for stability in the presence of water and found to retain most of their luminescent properties even in the presence of a large excess of water.

19.
Langmuir ; 26(9): 6091-6, 2010 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-20364860

RESUMO

Separation and subsequent culturing of MCF-7 breast cancer cells on self-assembled protein-coated magnetic beads in a microfluidic chip is demonstrated. The beads were patterned in situ inside a sealed microfluidic channel using magnetic-field-assisted electrostatic self-assembly. Hereafter, they were grafted by exposure to a solution of 5D10 monoclonal antibodies (mAb) and fibronectin (FN), with the first being used for immunospecific cell capture and the latter being used for cell adhesion and growth. A solution of target MCF-7 cells mixed with Jurkat cells was brought inside the microchannel, leading to specific MCF-7 cell capture; the latter were then cultured and evidenced by cell immuno-luminescence.


Assuntos
Neoplasias da Mama/patologia , Técnicas de Cultura de Células/instrumentação , Separação Celular/instrumentação , Magnetismo , Técnicas Analíticas Microfluídicas , Microesferas , Biomarcadores/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Adesão Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Células Jurkat , Medições Luminescentes
20.
Inorg Chem ; 49(8): 3927-36, 2010 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-20302272

RESUMO

Sterically hindered N-aryl-benzimidazole pyridine-2-carboxylic acids (aryl = phenyl, 4-biphenyl, 2-naphthyl) readily form homoleptic, neutral, nine-coordinate europium complexes which display efficient sensitized luminescence in solid state and in dichloromethane solution with quantum yields reaching 59% and have monoexponential and nearly temperature-independent lifetimes as long as 2.7 ms. The ligand-centered absorption band with a maximum at 321-342 nm and intensity (50-56) x 10(3) M(-1)cm(-1) ensures efficient harvesting of excitation light by the complexes. Variation of N-aryl chromophore enhances the ligand absorption at 250-350 nm without changing its triplet state energy which amounts to (19.2-21.3) x 10(3) cm(-1). Photophysical properties of europium complexes benefit from adequate protection of the metal by the ligands against non-radiative deactivation and efficient ligand-to-metal energy transfer exceeding 70%. A correlation is observed between the sensitized luminescence quantum yields of europium and the ligand triplet state energy; in certain cases it points to the presence of a second-sphere quenching of Eu(III) by co-crystallized water in the solid state.

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