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1.
Environ Sci Pollut Res Int ; 26(36): 36287-36295, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31713827

RESUMO

Preparation of the value-added products from e-waste resources is an important step in the recycling process. The present paper aims to propose a methodology for the recovery of In from scrap LCD panel via preparation of InBO3 nanostructure. Discarded LCD panel was subjected to a recycling process through crushing, milling, and oxalic acid leaching to prepare In2(C2O4)3·6H2O. Through the leaching process, B(OH)3 from glass part (alumina borosilicate) has been leached out along with indium oxalate hydrated. Further thermal treatment on these extracted materials at 600 °C could result in the formation of InBO3 nanostructures with an average particle size of 20 nm. A multistep mechanism based on thermodynamic calculations for the recycling of the InBO3 form extracted precursors was proposed. Graphical abstract.


Assuntos
Resíduo Eletrônico , Cristais Líquidos/química , Nanoestruturas/química , Reciclagem/métodos , Compostos de Boro/química , Vidro/química , Temperatura Alta , Índio/química , Ácido Oxálico/química , Tamanho da Partícula
2.
Chem Commun (Camb) ; 55(100): 15053-15056, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31777878

RESUMO

The present study reports an aqueous synthesis approach towards off-stoichiometric copper indium sulfide quantum dots with emissions in the near-infrared spectral range. The photoluminescence properties of the dots, and in particular the appearance of dual emission at high Cu deficiency, were studied with temperature-dependent steady-state and transient photoluminescence spectroscopy.


Assuntos
Materiais Biocompatíveis/química , Pontos Quânticos/química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular , Cobre/química , Células HeLa , Humanos , Índio/química , Medições Luminescentes , Pontos Quânticos/toxicidade , Temperatura Ambiente , Raios Ultravioleta
3.
Int J Nanomedicine ; 14: 7065-7078, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507320

RESUMO

Background:  Metal-free, water-soluble and highly stable meso-tetra-(4-sulfonatophenyl) porphyrin (TPPS4) has been studied for their singlet oxygen quantum yield. However, TPPS4 suffers from inherent shortcomings. To address these, TPPS4 was conjugated to ternary copper indium sulphide/ zinc sulphide (CuInS2/ZnS) quantum dots (QDs). Purpose:  We herein report for the first time the synthesis of TPPS4-CuInS/ZnS QDs conjugate as an improved photosensitizer. Methods:  Water-soluble TPPS4 was synthesized from tetraphenylporphyrin (TPPH2) after silica-gel purification. The CuInS/ZnS QDs were synthesized by hydrothermal method at a Cu:In ratio of 1:4. The porphyrin-QDs conjugate was formed via the daggling sulfonyl bond of the porphyrin and amine bond of the QDs. The effect of pH on the optical properties of TPPS4 was evaluated. The effect of Zn:Cu + In ratio on the ZnS shell passivation was examined to reduce structural defects on the as-synthesized QDs. Results : Various spectroscopic techniques were used to confirm the successful conversion of the organic TPPH2 to water-soluble TPPS4. The singlet oxygen generation evaluation shows an improved singlet oxygen quantum yield from 0.19 for the porphyrin (TPPS4) alone to 0.69 after conjugation (CuInS/ZnS-TPPS4) with an increase in the reaction rate constant (k (s-1)).


Assuntos
Cobre/química , Índio/química , Porfirinas/síntese química , Porfirinas/farmacologia , Pontos Quânticos/química , Sulfetos/síntese química , Compostos de Zinco/síntese química , Concentração de Íons de Hidrogênio , Fenômenos Ópticos , Fármacos Fotossensibilizantes , Porfirinas/química , Pontos Quânticos/ultraestrutura , Oxigênio Singlete/química , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfetos/química , Temperatura Ambiente , Compostos de Zinco/química
4.
Molecules ; 24(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31489942

RESUMO

Strong piezoresistivity of InAsP nanowires is rationalized with atomistic simulations coupled to Density Functional Theory. With a focal interest in the case of the As(75%)-P(25%) alloy, the role of crystal phases and phosphorus atoms in strain-driven carrier conductance is discussed with a direct comparison to nanowires of a single crystal phase and a binary (InAs) alloy. Our analysis of electronic structures presents solid evidences that the strong electron conductance and its sensitivity to external tensile stress are due to the phosphorous atoms in a Wurtzite phase, and the effect of a Zincblende phase is not remarkable. With several solid connections to recent experimental studies, this work can serve as a sound framework for understanding of the unique piezoresistive characteristics of InAsP nanowires.


Assuntos
Arsenicais/química , Índio/química , Nanofios/química , Fósforo/química , Teoria da Densidade Funcional , Condutividade Elétrica , Tamanho da Partícula , Propriedades de Superfície
5.
ACS Appl Mater Interfaces ; 11(39): 35630-35640, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31496235

RESUMO

Many attempts have been made to synthesize cadmium-free quantum dots (QDs), using nontoxic materials, while preserving their unique optical properties. Despite impressive advances, gaps in knowledge of their intracellular fate, persistence, and excretion from the targeted cell or organism still exist, precluding clinical applications. In this study, we used a simple model organism (Hydra vulgaris) presenting a tissue grade of organization to determine the biodistribution of indium phosphide (InP)-based QDs by X-ray fluorescence imaging. By complementing elemental imaging with In L-edge X-ray absorption near edge structure, unique information on in situ chemical speciation was obtained. Unexpectedly, spectral profiles indicated the appearance of In-O species within the first hour post-treatment, suggesting a fast degradation of the InP QD core in vivo, induced mainly by carboxylate groups. Moreover, no significant difference in the behavior of bare core QDs and QDs capped with an inorganic Zn(Se,S) gradient shell was observed. The results paralleled those achieved by treating animals with an equivalent dose of indium salts, confirming the preferred bonding type of In3+ ions in Hydra tissues. In conclusion, by focusing on the chemical identity of indium along a 48 h long journey of QDs in Hydra, we describe a fast degradation process, in the absence of evident toxicity. These data pave the way to new paradigms to be considered in the biocompatibility assessment of QD-based biomedical applications, with greater emphasis on the dynamics of in vivo biotransformations, and suggest strategies to drive the design of future applied materials for nanotechnology-based diagnosis and therapeutics.


Assuntos
Hydra/metabolismo , Índio , Fosfinas , Pontos Quânticos/química , Espectrometria por Raios X , Animais , Índio/química , Índio/farmacocinética , Índio/farmacologia , Fosfinas/química , Fosfinas/farmacocinética , Fosfinas/farmacologia
6.
Molecules ; 24(15)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370316

RESUMO

Aluminum-doped tin oxide (SnO 2:Al) thin films were produced by an ultrasonic spray pyrolysis method. The effect of aluminum doping on structural, optical, and electrical properties of tin oxide thin films synthesized at 420 ∘C was investigated. Al doping induced a change in the morphology of tin oxide films and yielded films with smaller grain size. SnO 2 thin films undergo a structural reordering and have a texture transition from (301) to (101), and then to (002) preferred cristallographic orientation upon Al doping. The lattice parameters (a and c) decreases with Al doping, following in a first approximation Vegard's law. The optical transmission does not change in the visible region with an average transmittance value of 72-81%. Conversely, in the near infrared (NIR) region, the plasmon frequency shifts towards the IR region upon increasing Al concentration in the grown films. Nominally undoped SnO 2 have a conductivity of ∼1120 S/cm, which is at least two orders of magnitude larger than what is reported in literature. This higher conductivity is attributed to the Cl- ions in the SnCl 4.5(H 2 O) precursor, which would act as donor dopants. The introduction of Al into the SnO 2 lattice showed a decrease of the electrical conductivity of SnO 2 due to compensating hole generation. These findings will be useful for further studied tackling the tailoring of the properties of highly demanded fluorine doped tin oxide (FTO) films.


Assuntos
Alumínio/química , Pirólise , Compostos de Estanho/química , Óxido de Zinco/química , Condutividade Elétrica , Índio/química , Espectrometria por Raios X , Compostos de Estanho/síntese química , Ultrassom
7.
Biosens Bioelectron ; 142: 111487, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31276907

RESUMO

This work designed a MgIn2S4-TiONA heterojunction by growing MgIn2S4 nanoplates on TiO2 nanowire array (TiONA) for preparation of visible light photoelectrochemical (PEC) sensing platform. The heterojunction exhibited strong absorption of visible light, large surface area and high loading of biomolecules, leading to high sensing sensitivity. Using adenosine triphosphate (ATP), a marker of cell vitality, as the target model, a PEC sandwich aptasensor was constructed by immobilizing capture DNA1 on MgIn2S4 surface. In the presence of ATP and signal DNA2 with terminal ferrocene as the electron donor, a sandwiched DNA1-ATP-DNA2 complex could be formed on the PEC aptasensor. The aptasensor showed excellent performance with a wide linear range from 50 fM to 100 nM and a detection limit of 20 fM. The sensing performance including specificity, reproducibility, stability and practical use were also evaluated, showing promising application of the MgIn2S4-TiONA heterojunction in PEC biosensing.


Assuntos
Trifosfato de Adenosina/sangue , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Nanoestruturas/química , Titânio/química , Trifosfato de Adenosina/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Desenho de Equipamento , Humanos , Índio/química , Luz , Limite de Detecção , Magnésio/química , Nanoestruturas/ultraestrutura , Enxofre/química
8.
Biosens Bioelectron ; 142: 111524, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351417

RESUMO

Herein, a highly efficient dual-quenching biosensor based on electrochemiluminescence resonance energy transfer (ECL-RET) is designed utilizing Ru-In2S3 as ECL acceptor and α-MoO3-Au as ECL donor. Compared α-MoO3-Au with pure α-MoO3, the overlapping peak area between ECL emission of Ru-In2S3 and UV-vis spectra of α-MoO3-Au is increased, indicated better quenching effect is obtained. Hollow In2S3 and α-MoO3-Au both have huge specific surface area to host a large amount of luminophores and antibodies. Moreover, HWRGWVC (H7) as specific capturer is adopted to achieve site-oriented antibody immobilization, which not only maintain antibody activity, but greatly improve the incubation process of antibodies, thus promoting the sensitivity of the biosensor. It's worth mentioning that the effect of over-potential on protein activity was proved in this work. The proposed biosensor obtained sensitive response by using PCT as a target with wide linear range from 0.0001 to 50 ng/mL and low detection limit of 12.49 fg/mL (S/N = 3), indicating its potential in the detection of biomarkers. Importantly, a novel ECL-RET pair of Ru-In2S3 (donor)/α-MoO3-Au (acceptor) is firstly developed, which opened an efficient way for highly sensitive detection of antibody in disease clinical and diagnosis analysis.


Assuntos
Anticorpos Imobilizados/química , Ouro/química , Medições Luminescentes/métodos , Molibdênio/química , Óxidos/química , Pró-Calcitonina/sangue , Rutênio/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Transferência de Energia , Humanos , Índio/química , Limite de Detecção , Nanocompostos/química , Nanocompostos/ultraestrutura
9.
Mater Sci Eng C Mater Biol Appl ; 102: 653-660, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147037

RESUMO

This paper reports an aptamer-based green approach for the electrochemical evaluation of tyrosinamide (Tyr-NH2). In this regard, at the first step, an aqueous synthetic strategy for preparing N-acetyl-l-cysteine (NAC)-capped Ag-In-S (AIS) quantum dots (QDs) with bright yellow/orange emission was developed. The conjugation of AIS QDs to NAC-biomolecules provides opportunities for using them as luminescent contrast agents for living cell tracking and labeling or sensing studies. In the next step, the design stage of the aptasensor, the glassy carbon electrode (GCE) was modified with the AIS QDs and then the Tyr-NH2 special aptamer, which has an amine group at its end, interacts with silver and indium ions at the surface of the AIS QDs and through the formation of covalent bonding of AgN and InN, attaches to the GCE surface modified with the AIS QDs. In this approach, for the first time, NAC-capped AIS QDs have been used to modify the electrode surface in the aptamer-based electrochemical sensor. The response changes of the [Fe(CN)6]4-/3- as redox probe, during the modification of GCE surface, the fabrication and assessment of proposed aptasensing, using the cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy were recorded. The designed aptasensor for the Tyr-NH2 evaluation showed good linearity from 0.01 to 2.81 nM and 2.81-10.81 nM, and low detection limit of 3.34 pM. The obtained results of the stability, reproducibility and selectivity investigations implying that the reported aptasensor as the first aptamer-based electrochemical assay for Tyr-NH2, can be reliable for the determination of Tyr-NH2 in serum samples.


Assuntos
Acetilcisteína/química , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Carbono/química , Técnicas Eletroquímicas/métodos , Vidro/química , Pontos Quânticos/química , Tirosina/análogos & derivados , Espectroscopia Dielétrica , Eletrodos , Humanos , Índio/química , Pontos Quânticos/ultraestrutura , Reprodutibilidade dos Testes , Prata/química , Enxofre/química , Fatores de Tempo , Tirosina/sangue
10.
Anal Bioanal Chem ; 411(20): 5277-5285, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161325

RESUMO

Rapid, highly sensitive detection of tau protein and other neurodegenerative biomarkers remains a significant hurdle for diagnostic tests for Alzheimer's disease. In this work, we developed a novel tyrosinase (TYR)-induced tau aptamer-tau-tau antibody (anti-tau) sandwich fluorescence immunoassay to detect tau protein that used dopamine (DA)-functionalized CuInS2/ZnS quantum dots as the fluorophore. CuInS2/ZnS core/shell quantum dots with high luminescence, low toxicity, and excellent biocompatibility were successfully fabricated and decorated with DA through amide conjugation. Meanwhile, TYR was conjugated with anti-tau by a click reaction. When DA-functionalized CuInS2/ZnS quantum dots were added to the sandwich system, TYR catalyzed the transformation of DA to dopamine quinone, which acted as an effective electron acceptor and triggered fluorescence quenching. The fluorescence intensity of the immunoassay based on DA-functionalized CuInS2/ZnS quantum dots shows good performance in terms of linearity with the logarithm of tau protein concentration, with a linear concentration range from 10 pM to 200 nM. This work is the first to use a TYR-induced fluorescence immunoassay for the rapid detection of tau protein, paving a new way for the detection of disease biomarkers. Graphical abstract.


Assuntos
Cobre/química , Imunofluorescência/métodos , Índio/química , Monofenol Mono-Oxigenase/química , Pontos Quânticos/química , Selênio/química , Sulfetos/química , Compostos de Zinco/química , Proteínas tau/análise , Cristalografia por Raios X , Dopamina/análogos & derivados , Dopamina/química , Microscopia Eletrônica de Transmissão , Análise Espectral/métodos
11.
Adv Mater ; 31(23): e1807552, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30985020

RESUMO

A colorimetric multifunctional phototransmittance-based structural durability monitoring system is developed. The system consists of an array with four indium gallium zinc oxide (IGZO)-based phototransistors, a light source at a wavelength of 405 nm through a side-emitting optical fiber, and pH- and Cl-selective color-variable membranes. Under illumination at the wavelength of 405 nm at corrosion status, the pH- and Cl-responsive membrane, showing a change in their color, generates a change in the intensity of the transmitted light, which is received by the phototransistor array in the form of an electrical current. Ids and R (Ids /IpH 12 ) are inversely proportional to the pH, which ranges from 10 to 12. When the pH drops from 12 to 10, the magnitude of Ids and R increases to ≈103 . In the case of Cl detection, Ids and R (Ids /ICl 0 wt% ) increase nearly 50 times with an increase in Cl concentration of 0.05 wt%, and when the Cl concentration reaches 0.30 wt%, Ids and R increase to ≈103 times greater. This multifunctional colorimetric durability sensing system demonstrates considerable potential as a novel smart-diagnostic tool of structural durability with high stability, high sensitivity, and multifunction.


Assuntos
Colorimetria/métodos , Materiais de Construção/análise , Cloretos/análise , Colorimetria/instrumentação , Tecnologia de Fibra Óptica/instrumentação , Tecnologia de Fibra Óptica/métodos , Gálio/química , Concentração de Íons de Hidrogênio , Índio/química , Luz , Membranas Artificiais , Fibras Ópticas , Óxido de Zinco/química
12.
Biosens Bioelectron ; 135: 88-94, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004925

RESUMO

It is essential to develop a highly efficient detection platform for tetracycline (Tc). Herein, based on well-designed hierarchical MIL-68(In)-NH2/MWCNT/CdS composites as a highly efficient transducer, a label-free visible light driven photoelectrochemical (PEC) aptasensor was systematically fabricated. Characterization results indicate that the forming of MIL-68(In)-NH2/CdS heterojunction remarkable facilitated the transfer and inhibited the recombination of charge carriers. Moreover, the transfer properties of multiwalled carbon nanotubes (MWCNTs) further improved the photoelectric conversion efficiency by adjusting electron transport routes. The aptamer as a biorecognition unit was grafted on the modified electrode by chemical bonding effect, and Tc molecules could be captured through the specific interaction of aptamer and Tc in solution. The concentration of Tc was detected by observing the fluctuation of photocurrent signals. Under optimized conditions, the proposed aptasensor showed the broad linear range from 0.1 nmol L-1 to 1 µmol L-1 with a low detection limit (LOD) of 0.015 nmol L-1. Furthermore, the high sensitivity, excellent reproducibility and favorable stability of the PEC sensing platform indicated the potential applications for antibiotic residues detecting in environmental media.


Assuntos
Antibacterianos/análise , Compostos de Cádmio/química , Estruturas Metalorgânicas/química , Nanotubos de Carbono/química , Compostos de Selênio/química , Tetraciclina/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Índio/química , Limite de Detecção , Poluentes Químicos da Água/análise
13.
Molecules ; 24(6)2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30875932

RESUMO

In this study, CuInS2/ZnS nanocrystals were synthesized by a two-step mechanochemical synthesis for the first time. In the first step, tetragonal CuInS2 was prepared from copper, indium and sulphur precursors. The obtained CuInS2 was further co-milled with zinc acetate dihydrate and sodium sulphide nonahydrate as precursors for cubic ZnS. Structural characterization of the CuInS2/ZnS nanocrystals was performed by X-ray diffraction analysis, Raman spectroscopy and transmission electron microscopy. Specific surface area of the product (86 m²/g) was measured by low-temperature nitrogen adsorption method and zeta potential of the particles dispersed in water was calculated from measurements of their electrophoretic mobility. Optical properties of the nanocrystals were determined using photoluminescence emission spectroscopy.


Assuntos
Cobre/química , Índio/química , Sulfetos/síntese química , Compostos de Zinco/química , Estrutura Molecular , Nanocompostos , Nanopartículas , Sulfetos/química , Propriedades de Superfície , Difração de Raios X
14.
Org Lett ; 21(7): 2200-2203, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30855974

RESUMO

Lantibiotics are a class of peptide antibiotics with activity against most Gram-positive bacteria. Lanthionine (Lan) and ß-MeLan are unusual thioether-bridged, non-proteinogenic amino acids, which are characteristic features of lantibiotics. In this paper, we report the facile stereoselective synthesis of ß-methyllanthionines with orthogonal protection by nucleophilic ring opening of aziridines. This method leads to an expedient access to ß-methyllanthionines and allows production of over 30 g of ß-methyllanthionine in a single batch.


Assuntos
Alanina/análogos & derivados , Aminoácidos/química , Aziridinas/química , Bactérias Gram-Positivas/efeitos dos fármacos , Índio/química , Sulfetos/síntese química , Alanina/síntese química , Alanina/química , Bactérias Gram-Positivas/química , Estrutura Molecular , Sulfetos/química
15.
J Colloid Interface Sci ; 542: 469-482, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30772509

RESUMO

The engineering of luminescent nanoplatforms for biomedical applications displaying ability for scaling-up, good colloidal stability in aqueous solutions, biocompatibility, and providing an easy detection in vivo by fluorescence methods while offering high potential of functionalities, is currently a challenge. The original strategy proposed here involves the use of large pore (ca. 15 nm) mesoporous silica (MS) nanoparticles (NPs) having a stellate morphology (denoted STMS) on which fluorescent InP/ZnS quantum dots (QDs) are covalently grafted with a high yield (≥90%). These nanoplatforms are after that further coated to avoid a potential QDs release. To protect the QDs from potential release or dissolution, two wrapping methods are developed: (i) a further coating with a silica shell having small pores (≤2 nm) or (ii) a tight polysaccharide shell deposited on the surface of these STMS@QDs particles via an original isobutyramide (IBAM)-mediated method. Both wrapping approaches yield to novel luminescent nanoplatforms displaying a highly controlled structure, a high size monodispersity (ca. 200 and 100 nm respectively) and colloidal stability in aqueous solutions. Among both methods, the IBAM-polysaccharide coating approach is shown the most suitable to ensure QDs protection and to avoid metal cation release over three months. Furthermore, these original STMS@QDs@polysaccharide luminescent nanoplatforms are shown biocompatible in vitro with murine cancer cells and in vivo after injections within zebrafish (ZF) translucent embryos where no sign of toxicity is observed during their development over several days. As assessed by in vivo confocal microscopy imaging, these nanoplatforms are shown to rapidly extravasate from blood circulation to settle in neighboring tissues, ensuring a remanent fluorescent labelling of ZF tissues in vivo. Such fluorescent and hybrid STMS composites are envisioned as novel luminescent nanoplatforms for in vivo fluorescence tracking applications and offer a versatile degree of additional functionalities (drug delivery, incorporation of magnetic/plasmonic core).


Assuntos
Materiais Biocompatíveis/química , Corantes Fluorescentes/química , Nanocompostos/química , Pontos Quânticos/química , Dióxido de Silício/química , Amidas/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Índio/química , Camundongos , Tamanho da Partícula , Fosfinas/química , Polissacarídeos/química , Porosidade , Espectrometria de Fluorescência , Sulfetos/química , Propriedades de Superfície , Peixe-Zebra/embriologia , Compostos de Zinco/química
16.
J Environ Sci (China) ; 79: 54-66, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30784464

RESUMO

Novel 3D biogenic C-doped Bi2MoO6/In2O3-ZnO Z-scheme heterojunctions were synthesized for the first time, using cotton fiber as template. The as-prepared samples showed excellent adsorption and photodegradation performance toward the hazardous antibiotic doxycycline under simulated sunlight irradiation. The morphology, phase composition and in situ carbon doping could be precisely controlled by adjusting processing parameters. The carbon doping in Bi2MoO6/In2O3-ZnO was derived from the cotton template, and the carbon content could be varied in the range 0.9-4.4 wt.% via controlling the heat treatment temperature. The sample with Bi2MoO6/In2O3-ZnO molar ratio of 1:2 and carbon content of 1.1 wt.% exhibited the highest photocatalytic activity toward doxycycline degradation, which was 3.6 and 4.3 times higher than those of pure Bi2MoO6 and ZnInAl-CLDH (calcined layered double hydroxides), respectively. It is believed that the Z-scheme heterojunction with C-doping, the 3D hierarchically micro-meso-macro porous structure, as well as the high adsorption capacity, contributed significantly to the enhanced photocatalytic activity.


Assuntos
Alumínio/química , Bismuto/química , Carbono/química , Índio/química , Molibdênio/química , Óxido de Zinco/química , Adsorção , Alumínio/efeitos da radiação , Antibacterianos/química , Carbono/efeitos da radiação , Fibra de Algodão , Doxiciclina/química , Índio/efeitos da radiação , Molibdênio/efeitos da radiação , Fotólise , Luz Solar , Óxido de Zinco/efeitos da radiação
17.
Carbohydr Res ; 474: 34-42, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30711766

RESUMO

Legionaminic acid and 4-epi-legionaminic acid are 5,7-diacetamido nonulosonic acids and are assumed to play a crucial role in the virulence of Legionella pneumophila, the causative agent of Legionnaires' disease. Moreover, they are ideal target motifs for the development of vaccines and pathogen detection. Herein, we present a versatile de novo synthesis of legionaminic acid and 4-epi-legionaminic acid. Starting from simple d-serine, the C9-backbone is built up by two CC-bond formation reactions. First, the protected d-serine motif is elongated utilizing a highly stereoselective nitroaldol reaction to give a C6-precursor of desired d-rhamno configuration. Second, an indium-mediated allylation is employed to further elongate the carbon backbone and introduce a masked α-keto acid function.


Assuntos
Técnicas de Química Sintética , Compostos Heterocíclicos com 3 Anéis/química , Nitrocompostos/química , Serina/química , Ácidos Siálicos/síntese química , Açúcares Ácidos/química , Catálise , Humanos , Índio/química , Cinética , Legionella pneumophila/metabolismo , Estrutura Molecular , Estereoisomerismo
18.
Methods Appl Fluoresc ; 7(3): 035008, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-30654340

RESUMO

InP/ZnS quantum dot (QD)-based fluorescent probe for directly sensitive and selective detection of horseradish peroxidase (HRP) was reported herein. Fluorescence of InP/ZnS QDs was statically quenched by HRP, due to the ground state complex formation of InP/ZnS QDs with HRP. Such ground state complex formation between InP/ZnS QDs and HRP reduced both the α-helix content and the melting temperature of HRP. Several key factors including InP/ZnS QDs concentration, buffer pH value, ionic strength, reaction temperature, and reaction time those affected the analytical performance of InP/ZnS QDs in HRP determination were investigated thoroughly. Under the optimal conditions, fluorescence intensity of InP/ZnS QDs was linearly decreased with the increasing of HRP concentration during the range of 1.0 × 10-9 M âˆ¼ 3.0 × 10-8 M (0.01 U ml-1 âˆ¼ 0.3 U ml-1) with the detection limit as low as 1.2 × 10-10 M (1.2 mU ml-1). The present method showed excellent selectivity for HRP over some amino acids, nucleotides, and common proteins. This method was utilized to detect HRP in synthetic samples successfully.


Assuntos
Corantes Fluorescentes/química , Peroxidase do Rábano Silvestre/análise , Índio/química , Fosfinas/química , Pontos Quânticos/química , Sulfetos/química , Compostos de Zinco/química , Armoracia/enzimologia , Ensaios Enzimáticos/métodos , Limite de Detecção , Sensibilidade e Especificidade , Espectrometria de Fluorescência/métodos
19.
Lab Chip ; 19(5): 807-814, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30681103

RESUMO

A liquid-metal based capacitive soft pressure microsensor is proposed in this work for measuring pressure in microchannels. To measure the pressure of the target microchannel, a short detection channel is fabricated and connected to the target microchannel. Because the detection channel has only one outlet at the end which is connected to the target microchannel, the fluid in the detection channel will stay still during the measurement and the pressure remains constant inside the detection channel. A segment of reference fluid which is immiscible with the working fluid is sealed inside the detection channel. Because the chip material is soft, the pressure change will lead to the movement of the interface between the reference fluid and working fluid inside the detection channel. A pair of liquid metal electrodes are fabricated on both sides of the detection channel. By measuring the capacitance between these two liquid metal electrodes, the movement of the interface can be detected, and thus the pressure change can be detected as well. To minimize the influence from the environment, two liquid metal shield layers are placed on the top and the bottom of the microchannel layer separately. The microsensor was first tested in a microfluidic system and then utilized to measure the blood pressure of rabbit carotid artery in vivo. The experimental results showed excellent stability and linear correlation between capacitance and the value of fluid pressure. The pressure sensor can achieve a resolution of 7.5 mmHg within a pressure range of 20-300 mmHg. This work provides a promising approach to develop an implantable blood or intraocular pressure-monitoring device for clinical use.


Assuntos
Pressão Sanguínea , Gálio/química , Índio/química , Técnicas Analíticas Microfluídicas , Estanho/química , Animais , Artérias Carótidas , Eletrodos , Desenho de Equipamento , Técnicas Analíticas Microfluídicas/instrumentação , Coelhos
20.
Mater Sci Eng C Mater Biol Appl ; 97: 583-592, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30678945

RESUMO

In this work core/shell cadmium-free zinc­copper­indium sulfide ZnCuInS/ZnS quantum dots (QDs) originally stabilized with hydrophilic alkanethiol were modified with 3-mercaptopropionic acid (MPA) or 6-mercaptohexanoic acid (MHA) via two-step ligand exchange method. The obtained QDs were further characterized by TEM, UV Vis, and fluorescence spectroscopy. Both types of QDs were non-toxic in a wide range of concentrations. To our knowledge, our studies are the first attempt to determine the type of cell death and reactive oxygen species production level as a result of incubation of cell cultures with ZnCuInS/ZnS QDs. Furthermore, the accumulation of QDs in vitro was examined on three human cell lines by fluorescence intensity measurements and visualized by confocal microscopy. The modification of QDs with a ligand characterized by slightly longer aliphatic chain (MHA), instead of typically used MPA turns out to be beneficial both from the point of colloidal stability, preservation of optical properties during ligand exchange as well as reflects in a higher cellular uptake. This contribution can be beneficial from the point of view of the selection of the optimal ligands and concentrations in the case of ZnCuInS/ZnS core-shell QDs for biological applications.


Assuntos
Ácido 3-Mercaptopropiônico/química , Ácidos Picolínicos/química , Pontos Quânticos/química , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Coloides/química , Cobre/química , Humanos , Índio/química , Ligantes , Microscopia Confocal , Pontos Quânticos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Sulfetos/química , Zinco/química
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