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1.
J Vis Exp ; (160)2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32658181

RESUMO

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers are directly grown on NPSS using catalyst-free atmospheric-pressure chemical vapor deposition (APCVD). By applying nitrogen reactive ion etching (RIE) plasma treatment, defects are introduced into the graphene film to enhance chemical reactivity. During metal-organic chemical vapor deposition (MOCVD) growth of AlN, this N-plasma treated graphene buffer enables AlN quick growth, and coalescence on NPSS is confirmed by cross-sectional scanning electron microscopy (SEM). The high quality of AlN on graphene-NPSS is then evaluated by X-ray rocking curves (XRCs) with narrow (0002) and (10-12) full width at half-maximum (FWHM) as 267.2 arcsec and 503.4 arcsec, respectively. Compared to bare NPSS, AlN growth on graphene-NPSS shows significant reduction of residual stress from 0.87 GPa to 0.25 Gpa, based on Raman measurements. Followed by AlGaN multiple quantum wells (MQWS) growth on graphene-NPSS, AlGaN-based deep ultraviolet light-emitting-diodes (DUV LEDs) are fabricated. The fabricated DUV-LEDs also demonstrate obvious, enhanced luminescence performance. This work provides a new solution for the growth of high quality AlN and fabrication of high performance DUV-LEDs using a shorter process and less costs.


Assuntos
Óxido de Alumínio/química , Grafite/química , Nanoestruturas/química , Semicondutores , Raios Ultravioleta , Compostos de Alumínio/química , Catálise , Gálio/química , Gases/química , Luminescência , Volatilização
2.
Nat Commun ; 11(1): 2405, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415064

RESUMO

Fiber-based electronics enabling lightweight and mechanically flexible/stretchable functions are desirable for numerous e-textile/e-skin optoelectronic applications. These wearable devices require low-cost manufacturing, high reliability, multifunctionality and long-term stability. Here, we report the preparation of representative classes of 3D-inorganic nanofiber network (FN) films by a blow-spinning technique, including semiconducting indium-gallium-zinc oxide (IGZO) and copper oxide, as well as conducting indium-tin oxide and copper metal. Specifically, thin-film transistors based on IGZO FN exhibit negligible performance degradation after one thousand bending cycles and exceptional room-temperature gas sensing performance. Owing to their great stretchability, these metal oxide FNs can be laminated/embedded on/into elastomers, yielding multifunctional single-sensing resistors as well as fully monolithically integrated e-skin devices. These can detect and differentiate multiple stimuli including analytes, light, strain, pressure, temperature, humidity, body movement, and respiratory functions. All of these FN-based devices exhibit excellent sensitivity, response time, and detection limits, making them promising candidates for versatile wearable electronics.


Assuntos
Nanopartículas Metálicas/química , Nanofibras/química , Dispositivos Eletrônicos Vestíveis , Consumo de Bebidas Alcoólicas , Técnicas Biossensoriais , Testes Respiratórios , Cobre/química , Elastômeros , Etanol/análise , Análise de Elementos Finitos , Gálio/química , Humanos , Índio/química , Teste de Materiais , Movimento (Física) , Poliestirenos/química , Semicondutores , Espectrofotometria Ultravioleta , Temperatura , Têxteis , Óxido de Zinco/química
3.
J Vis Exp ; (158)2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32421009

RESUMO

The presented protocol combines excellent detection limits (1 ppm to 1 ppb) using secondary ion mass spectrometry (SIMS) with reasonable spatial resolution (~1 µm). Furthermore, it describes how to obtain realistic three-dimensional (3D) distributions of segregated impurities/dopants in solid state materials. Direct 3D depth profile reconstruction is often difficult to achieve due to SIMS-related measurement artifacts. Presented here is a method to identify and solve this challenge. Three major issues are discussed, including the i) nonuniformity of the detector being compensated by flat-field correction; ii) vacuum background contribution (parasitic oxygen counts from residual gases present in the analysis chamber) being estimated and subtracted; and iii) performance of all steps within a stable timespan of the primary ion source. Wet chemical etching is used to reveal the position and types of dislocation in a material, then the SIMS result is superimposed on images obtained via scanning electron microscopy (SEM). Thus, the position of agglomerated impurities can be related to the position of certain defects. The method is fast and does not require sophisticated sample preparation stage; however, it requires a high-quality, stable ion source, and the entire measurement must be performed quickly to avoid deterioration of the primary beam parameters.


Assuntos
Gálio/química , Microscopia Eletrônica de Varredura , Espectrometria de Massa de Íon Secundário/métodos
4.
PLoS One ; 15(4): e0231179, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240256

RESUMO

Site-specific atom probe tomography (APT) from aluminum alloys has been limited by sample preparation issues. Indeed, Ga, which is conventionally used in focused-ion beam (FIB) preparations, has a high affinity for Al grain boundaries and causes their embrittlement. This leads to high concentrations of Ga at grain boundaries after specimen preparation, unreliable compositional analyses and low specimen yield. Here, to tackle this problem, we propose to use cryo-FIB for APT specimen preparation specifically from grain boundaries in a commercial Al-alloy. We demonstrate how this setup, easily implementable on conventional Ga-FIB instruments, is efficient to prevent Ga diffusion to grain boundaries. Specimens were prepared at room temperature and at cryogenic temperature (below approx. 90K) are compared, and we confirm that at room temperature, a compositional enrichment above 15 at.% of Ga is found at the grain boundary, whereas no enrichment could be detected for the cryo-prepared sample. We propose that this is due to the decrease of the diffusion rate of Ga at low temperature. The present results could have a high impact on the understanding of aluminum and Al-alloys.


Assuntos
Ligas/química , Alumínio/química , Tomografia/métodos , Gálio/química , Íons , Temperatura
5.
Phys Chem Chem Phys ; 22(12): 6706-6715, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32162626

RESUMO

In the present study, we systematically investigated the adsorption mechanism of canonical DNA nucleobases and their two nucleobase pairs on a single-layer gallium sulfide (GaS) substrate using DFT+D3 methods. The GaS substrate has chemical interactions with molecules 0.02 |e| 0.11 |e| from molecules to the monolayer GaS surface. Due to the chemical interactions of adenine, cytosine, guanine, and thymine on the monolayer GaS surface, the work function is decreased by 0.69, 0.60, 0.97, and 0.20 eV, respectively. It is displayed that the bandgap of the monolayer GaS sheet can be significantly affected as induced molecular electronic states tend to appear near the Fermi level region due to chemical and physisorption mechanism. We have also investigated the transport properties of DNA nucleobases, namely, AT and GC pair molecules on the GaS surface, which shows significant reduction in the zero-bias transmission spectra. Moreover, with and without DNA nucleobases, namely, AT and GC pair molecules' absorptions on the GaS surface, clearly expressed in terms of distinct current signals, can be observed as ON and OFF states for this device. The distinctive nucleobase adsorption energies and different I-V responses may serve as potential probes for the selective detection of nucleobase molecules in imminent DNA sequencing applications based on a monolayer GaS surface.


Assuntos
Sequência de Bases , DNA/química , Gálio/química , Sulfetos/química , DNA/análise , Estrutura Molecular
6.
Chemistry ; 26(34): 7602-7608, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32068310

RESUMO

In this study a bispidine ligand has been applied to the complexation of gallium(III) and radiolabelled with gallium-68 for the first time. Despite its 5-coordinate nature, the resulting complex is stable in serum for over two hours, demonstrating a ligand system well matched to the imaging window of gallium-68 positron emission tomography (PET). To show the versatility of the bispidine ligand and its potential use in PET, the bifunctional chelator was conjugated to a porphyrin, producing a PET/PDT-theranostic, which showed the same level of stability to serum as the non-conjugated gallium-68 complex. The PET/PDT complex killed >90 % of HT-29 cells upon light irradiation at 50 µm. This study shows bispidines have the versatility to be used as a ligand system for gallium-68 in PET.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Quelantes/química , Gálio/química , Porfirinas/química , Compostos Bicíclicos Heterocíclicos com Pontes/análise , Radioisótopos de Gálio , Humanos , Ligantes , Tomografia por Emissão de Pósitrons/métodos , Nanomedicina Teranóstica/métodos
7.
Dalton Trans ; 49(8): 2734-2746, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32064490

RESUMO

Chemotherapeutic metal-based compounds are effective anticancer agents; however, their cytotoxic profile and significant side effects limit their wide application. Natural products, especially flavonoids, are a prominent alternative source of anticancer agents that can be used as ligands for the generation of new bioactive complexes with metal ions of known biochemical and pharmacological activities. Herein, we present the synthesis and detailed structural and physicochemical characterizations of three novel complex assemblies of Ga(iii) with the flavonoid chrysin and the ancillary aromatic chelators 1,10-phenanthroline, 2,2'-bipyridine and imidazole. The complexes constitute the only crystallographically characterized structures having a metal core from the boron group elements and a flavonoid as the ligand. The in vitro biological evaluation of the three complexes in a series of cancer cell lines of different origin established their cytotoxicity and ROS generating potential. In particular, the Ga(iii)-chrysin-imidazole complex displayed the highest anticancer efficacy against all cancer cell lines with IC50 values in the low micromolar range (<1.18 µM), a result worth further investigation.


Assuntos
Antineoplásicos/farmacologia , Flavonoides/química , Gálio/química , Neoplasias/tratamento farmacológico , Antineoplásicos/química , Proliferação de Células , Humanos , Estrutura Molecular , Neoplasias/patologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas
8.
Chemosphere ; 249: 126099, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32059149

RESUMO

Indium and gallium are used widely in modern industry, mostly for the production of semiconductors. They are considered as Technology-Critical Elements and have therefore received growing attention in the past few years. We investigated the influence of different types of humic substances on the transport of indium and gallium in laboratory-scale, saturated column experiments, to gain understanding of their mobility in natural environments. We evaluated the effect of different humic substances on the transport of indium and gallium in quartz sand: a commercial humic acid (Aldrich Humic Acid, AHA), a fulvic acid (Suwannee River Fulvic Acid, SRFA) and an aquatic natural organic matter (Suwannee River Natural Organic Matter, SRNOM). The impact of the flow rate and the influence of different concentrations of organic matter were also investigated. Indium was shown to be more mobile than gallium in the presence of humic substances. The mobility of indium in sand was highest for SRNOM, followed by SRFA and then AHA, while for gallium the order was SRFA > SRNOM > AHA. These results can be significant in understanding the mobility of indium and gallium in soils with various compositions of organic matter.


Assuntos
Gálio/química , Substâncias Húmicas/análise , Índio/química , Benzopiranos , Modelos Químicos , Porosidade , Rios , Solo
9.
Dalton Trans ; 49(6): 1947-1954, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-31976498

RESUMO

A series of solid solution CaAl12-xGaxO19:Mn4+ phosphors were prepared via a high-temperature solid-state reaction. Their structural properties were characterized by X-ray diffraction (XRD) and the luminescence was investigated via photoluminescence spectra. The obtained CaAl12-xGaxO19:Mn4+ phosphor has a strong broad excitation band in the range of 250-550 nm, which can be easily excited by the UV, NUV and blue light, and a broad emission band centered at 655 nm between 600 nm and 800 nm due to the 2Eg → 4A2g transition of the Mn4+ ion. The PL spectra indicate that the intensity of CaAl12O19:Mn4+ can be enhanced when the Ga3+ concentration equals 1. Furthermore, the element mapping, optical properties, thermal stability, fluorescence lifetime and CIE chromaticity reveal that the CaAl12-xGaxO19:Mn4+ phosphors can be considered as potential candidates in indoor plant cultivation.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Gálio/química , Substâncias Luminescentes/química , Manganês/química , Iluminação/métodos , Luminescência , Medições Luminescentes , Desenvolvimento Vegetal , Difração de Raios X
10.
Chem Commun (Camb) ; 56(10): 1509-1512, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31917383

RESUMO

Gallium(iii) complexes with polypridyl ligands are shown to kill bulk osteosarcoma cells and osteosarcoma stem cells (OSCs) with up to nanomolar potency. The most effective complex induces apoptosis in osteosarcoma cells by damaging genomic DNA. To the best of our knowledge this is the first investigation into metal-based anti-OSC agents.


Assuntos
Complexos de Coordenação/farmacologia , Gálio/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Linhagem Celular Tumoral , Núcleo Celular/química , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Humanos , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Osteossarcoma/metabolismo , Osteossarcoma/patologia
11.
Nat Commun ; 11(1): 326, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31949147

RESUMO

Bioinspired electronics are rapidly promoting advances in artificial intelligence. Emerging AI applications, e.g., autopilot and robotics, increasingly spur the development of power devices with new forms. Here, we present a strain-controlled power device that can directly modulate the output power responses to external strain at a rapid speed, as inspired by human reflex. By using the cantilever-structured AlGaN/AlN/GaN-based high electron mobility transistor, the device can control significant output power modulation (2.30-2.72 × 103 W cm-2) with weak mechanical stimuli (0-16 mN) at a gate bias of 1 V. We further demonstrate the acceleration-feedback-controlled power application, and prove that the output power can be effectively adjusted at real-time in response to acceleration changes, i.e., ▵P of 72.78-132.89 W cm-2 at an acceleration of 1-5 G at a supply voltage of 15 V. Looking forward, the device will have great significance in a wide range of AI applications, including autopilot, robotics, and human-machine interfaces.


Assuntos
Inteligência Artificial , Reflexo/fisiologia , Robótica/instrumentação , Robótica/métodos , Transistores Eletrônicos , Compostos de Alumínio/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Elétrons , Gálio/química , Humanos
12.
Eur J Med Chem ; 186: 111895, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31771825

RESUMO

A series of eight alkyl gallium complexes of general formulae [GaMe2(L)] and [Ga(Me)2L] have been synthesised, characterised and their antimicrobial activity against bacteria, cancer cells and Leishmania assessed. All eight complexes are novel, with the solid-state structures of all complexes successfully authenticated by single crystal X-ray diffraction. The dimethyl complexes all adopt a four-coordinate tetrahedral confirmation, while the monomethyl complexes are five-coordinate trigonal bipyramidal. All complexes were screened for their anti-bacterial activity either by solution state diffusion, or a solid-state stab test. The five soluble complexes underwent testing against two differing mammalian cell controls, with excellent selectivity observed against COS-7 cells, with an IC50 range of 88.5 µM to ≥100 µM. Each soluble complex was also tested for their anti-cancer capabilities, with no significant activity observed. Excellent activity was exhibited against the protozoan parasite Leishmania major (strain: V121) in both the promastigote and amastigote forms, with IC50 values ranging from 1.11 µM-13.4 µM for their anti-promastigote activity and % infection values of 3.5% ± 0.65-11.5% ± 0.65 for the more clinically relevant amastigote. Selectivity indices for each were found to be in the ranges of 6.61-64.7, with significant selectivity noted for two of the complexes. At minimum, the gallium complexes show a 3-fold enhancement in activity towards the Leishmaniaamastigotes over the parent quinolinols alone.


Assuntos
Antiprotozoários/farmacologia , Complexos de Coordenação/farmacologia , Gálio/farmacologia , Hidroxiquinolinas/farmacologia , Leishmania major/efeitos dos fármacos , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Células COS , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Chlorocebus aethiops , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Relação Dose-Resposta a Droga , Gálio/química , Células HeLa , Humanos , Hidroxiquinolinas/química , Leishmania major/metabolismo , Camundongos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Espécies Reativas de Oxigênio/análise , Relação Estrutura-Atividade
13.
J Photochem Photobiol B ; 202: 111685, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31810035

RESUMO

Surface tailored GaAu loaded mesoporous silica nanoparticles are considered as an important nanomaterial for biomedical applications such as diagnosis and cancer treatment. In this study, we used GaAu loaded mesoporous silica nanoparticles (Ga-Au@mSiO2) for the photothermal treatment of two prostate cancer cell lines. We systematically examined the nanocomposite form by various spectroscopic (UV-Vis, TGA and DTA) and electroscopic techniques (TEM and SEM including the elemental mapping analysis). After careful evaluation of the nanocomposite form, we performed cancer cell growth inhibition properties of the prostate cancer cell lines (DU145 and LNCaP). Also, we performed the photothermal effects of these nanocomposites on cell proliferation and apoptosis using different biochemical staining and flow cytometry. Our in vitro investigational datas are established Ga-Au@mSiO2 effectively exhibited and also with Ga-Au@mSiO2 + NIR the photothermal conversion therapy improved prostate cancer cells abolishing the prostate cancer cells. Interestingly, Ga-Au@mSiO2 + NIR was found to surpass the activity of Ga-Au@mSiO2 in all the cancer cells tested a topnotches. Hence, our current results demonstrated that surface tailored GaAu loaded mesoporous silica nanoparticles significantly inhibited the growth of prostate cancer cell lines and shown prominent antitumor effect in vitro. Thus, our study suggests that Ga-Au@mSiO2 + NIR could be used as impending anticancer candidate for photothermal ablation of prostate cancer cells. Further examinations of the mechanism indicated that anticancer activity was accomplished by inducing apoptosis in cancer cells, which is suggesting that these Ga-Au@mSiO2 + NIR nanocomposite can be used as promising candidates for nursing care cancer therapy.


Assuntos
Gálio/química , Ouro/química , Raios Infravermelhos , Nanocompostos/química , Neoplasias da Próstata/terapia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Humanos , Masculino , Nanocompostos/uso terapêutico , Nanocompostos/toxicidade , Cuidados de Enfermagem , Fototerapia , Porosidade , Neoplasias da Próstata/patologia , Dióxido de Silício/química
14.
Artigo em Inglês | MEDLINE | ID: mdl-31607225

RESUMO

III-V semiconductor materials such as gallium arsenide (GaAs) and indium arsenide (InAs) are increasingly used in the fabrication of electronic devices. There is a growing concern about the potential release of these materials into the environment leading to effects on public and environmental health. The waste effluents from the chemical mechanical planarization process could impact microorganisms in biological wastewater treatment systems. Currently, there is only limited information about the inhibition of gallium- and indium-based nanoparticles (NPs) on microorganisms. This study evaluated the acute toxicity of GaAs, InAs, gallium oxide (Ga2O3), and indium oxide (In2O3) particulates using two microbial inhibition assays targeting methanogenic archaea and the marine bacterium, Aliivibrio fischeri. GaAs and InAs NPs were acutely toxic towards these microorganisms; Ga2O3 and In2O3 NPs were not. The toxic effect was mainly due to the release of soluble arsenic species and it increased with decreasing particle size and with increasing time due to the progressive corrosion of the NPs in the aqueous bioassay medium. Collectively, the results indicate that the toxicity exerted by the arsenide NPs under environmental conditions will vary depending on intrinsic properties of the material such as particle size as well as on the dissolution time and aqueous chemistry.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Gálio/toxicidade , Índio/toxicidade , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/metabolismo , Arsenicais/química , Gálio/química , Índio/química , Metano/biossíntese , Nanopartículas/química , Tamanho da Partícula , Semicondutores , Esgotos/microbiologia , Propriedades de Superfície , Poluentes Químicos da Água/química , Purificação da Água/métodos
15.
Talanta ; 206: 120206, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514889

RESUMO

Hemoglobin (Hb) plays an important role in oxygen carriage for mammals, which is also a typical biomarker for certain diseases. Although numerous methods had been developed for the detection of Hb in red blood cells, analytical technology for the monitoring of low-abundance Hb in serum or plasma is still a challenge. Herein, persistent luminescence nanoparticles (PLNPs) with strong near-infrared (NIR) emission character behaving as a label-free probe for the highly sensitive and selective detection of Hb were developed. Further studies revealed that the sensing mechanism should be attributed to the Hb-induced dynamic quenching process. Moreover, the nanoprobe showed high selectivity to Hb against the common existing substances in human serum and a linear response to Hb ranging from 1 to 50 nM with an extremely high limit of detection (LOD) of 0.13 nM. Finally, applicability of the proposed probe for the detection of Hb in human serum samples was validated.


Assuntos
Hemoglobinas/análise , Substâncias Luminescentes/química , Nanopartículas Metálicas/química , Cromo/química , Gálio/química , Humanos , Limite de Detecção , Luminescência , Medições Luminescentes/métodos , Tamanho da Partícula , Zinco/química
16.
Chemosphere ; 239: 124722, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494318

RESUMO

Perfluorooctanoic acid (PFOA) has attracted considerable attention worldwide due to its widespread occurrence and environmental impacts. This research focused on the photocatalytic process for the treatment of PFOA in water and wastewater. Gallium oxide (Ga2O3) and peroxymonosulfate (PMS) were mixed directly in PFOA solution, which was irradiated under different light sources. The treatment system showed excellent performance that 100% PFOA was degraded within 90 min and 60 min under 254 nm and 185 nm UV irradiation, respectively. Moreover, the degradation efficacy was unaffected by initial PFOA concentration from 50 ng L-1 to 50 mg L-1. Acidic solution (pH 3) improved the degradation process. The quantum yield in the PMS/Ga2O3 system under UV light (254 nm) was estimated to be 0.009 mol E-1. Scavengers such as tert-butanol (t-BuOH), disodium ethylenediaminetetraacetate (EDTA-Na2) and benzoquinone (BQ) were added into PFOA solution to prove that sulfate radicals (SO4•-), superoxide radical (O2•-) and photogenerated electrons (e-) were the main active species with strong redox ability for PFOA degradation in PMS/Ga2O3/UV system. Combined with the intermediates analysis, PFOA was degraded stepwise from long chain compound to shorter chain intermediates. In addition, PFOA in real wastewater exhibited similar degradation efficiency, together with 75-85% TOC removal by Ga2O3/PMS under 254 nm UV irradiation. Therefore, Ga2O3/PMS system was highly effective for PFOA photodegradation under UV irradiation, which has potential to be applied for the perfluoroalkyl substances (PFAS) treatment in water and wastewater.


Assuntos
Caprilatos/química , Fluorcarbonetos/química , Gálio/química , Peróxidos/química , Poluentes Químicos da Água/química , Benzoquinonas/química , Ácido Edético/química , Concentração de Íons de Hidrogênio , Oxirredução , Fotólise , Superóxidos/química , Raios Ultravioleta , Águas Residuárias/química , Água , Purificação da Água , Difração de Raios X
17.
Talanta ; 208: 120438, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816755

RESUMO

The threatening of antibiotic drugs for human and environment is being paid more and more attention. Ciprofloxacin (CIP), a strong quinolone antibiotic drug widely used in therapeutic treatments, is the most frequently detected in surface waters among the fluoroquinolones, which represents animal and human health risks. A novel highly fluorescent Ga-based hybrid (Eu3+@1) has been synthesized based on metal-organic framework (MOF) by encapsulating lanthanide cations Eu3+ in its channels. The as-synthesized compound possesses excellent water and pH-independent stability. It displays week red luminescence of Eu3+ in itself and can sense the CIP concentration as turn-on fluorescent probe in the human urine. With addition of CIP, the evident luminescence enhancement is clearly observed from the Eu3+@1. Linear correlation between the fluorescence intensity and the concentration of CIP is investigated, proving the excellent performance of Eu3+@1 in the detection of CIP with linear range (0.01-0.2 mg/mL) and low detection limit (2.4 ppm or 2.4 µg/mL). The response time is also very quick, less than 3 min. Based on these findings, we introduce AND logic gate strategy to the probe. The input of the logic gates (0, 1), (0, 1, 1), (1, 1, 1) cause the different outputs of CIP determination "LOW" (<25 ppm),"NORMAL" (25-76 ppm), "HIGH" (>76 ppm), respectively. The novel strategy can be applied for a real-time CIP concentration evaluation by intelligent discrimination.


Assuntos
Antibacterianos/urina , Ciprofloxacino/urina , Európio/química , Corantes Fluorescentes/química , Gálio/química , Estruturas Metalorgânicas/química , Antibacterianos/química , Ciprofloxacino/química , Humanos , Lógica , Luminescência
18.
Biosens Bioelectron ; 147: 111784, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654823

RESUMO

This paper presents a microwave sensor designed as a capacitive matrix for label-free Escherichia coli detection. The mean value of capacitances' change in the capacitive matrix sensor is an indicator of the bacteria detection. The theoretical analysis was confirmed by the realization of an exemplary sensor chip manufactured using the United Monolithic Semiconductor (UMS) PH25 process on a 100 µm thick GaAs substrate and measurements of various concentrations of Escherichia coli in the frequency range 1-3 GHz. The matrix topology of the sensor together with biofunctionalization of the sensor surface with polyclonal anti-Escherichia coli antibody allow to obtain high detection sensitivity on various concentrations of Escherichia coli reaching 103 CFU/ml. The obtained results are promising for future biomedical applications, in terms of specific bacteria presence detection.


Assuntos
Técnicas Biossensoriais , Infecções por Escherichia coli/diagnóstico , Escherichia coli/isolamento & purificação , Arsenicais/química , Capacitância Elétrica , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Gálio/química , Humanos , Micro-Ondas
19.
Int J Mol Sci ; 20(23)2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31795220

RESUMO

InPBi exhibits broad and strong photoluminescence at room temperature, and is a potential candidate for fabricating super-luminescence diodes applied in optical coherence tomography. In this paper, the strained InPBi quantum dot (QD) embedded in the AlGaAs barrier on a GaAs platform is proposed to enhance the light emission efficiency and further broaden the photoluminescence spectrum. The finite element method is used to calculate the strain distribution, band alignment and confined levels of InPBi QDs. The carrier recombinations between the ground states and the deep levels are systematically investigated. A high Bi content and a flat QD shape are found preferable for fabricating super-luminescence diodes with high efficiency and a broad emission spectrum.


Assuntos
Pontos Quânticos/química , Arsênico/química , Bismuto/química , Gálio/química , Índio/química , Luminescência , Fósforo/química
20.
ACS Appl Mater Interfaces ; 11(48): 44978-44988, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31722170

RESUMO

Near-infrared (NIR) persistent luminescence (PersL) nanoparticles based on trivalent chromium-doped gallates (ZGO) as nanocarriers show great potential for theranostics, owing to their autofluorescence-free background and deep tissue penetration. However, high drug loading capacity of ZGO nanocarriers remains a big challenge. Herein, raspberry-like mesoporous Zn1.07Ga2.34Si0.98O6.56:Cr0.01 (designated as Si-ZGO) is first developed via a unique silica-assisted targeted etching strategy. The composition, morphology, NIR PersL capacities, and drug loading/releasing abilities of Si-ZGO have been explored. These results exhibit that Si-ZGO possess multiple inspiring characteristics including (i) spherical raspberry-like mesoporous morphology with a large cavity (total pore size ∼5.0 nm) and high specific surface area (∼80.653 m2·g-1), promising excellent drug loading capacity (∼62 wt %); (ii) tunable sizes from 80 to 180 nm and improved aqueous-dispersibility, facilitating cellular uptake and permeation and retention (EPR) effect; (iii) new deep traps related to oxygen vacancies, achieving the brighter NIR PersL. These outstanding merits enable the further nanosystem (DOX-BSA@Si-ZGO) for proof-of-concept theranostics excellent chemotherapy effect, tumor-specific trackable ability, and pronounced NIR afterglow imaging in vivo. This work demonstrates the great potentials of Si-ZGO nanorasperries as a multifunctional theranostics platform, even more it hopefully could inspire other constructions of advanced functional materials.


Assuntos
Antineoplásicos/administração & dosagem , Cromo/química , Gálio/química , Neoplasias/tratamento farmacológico , Dióxido de Silício/química , Zinco/química , Animais , Antineoplásicos/química , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Humanos , Raios Infravermelhos , Masculino , Camundongos , Camundongos Nus , Nanopartículas/química , Neoplasias/diagnóstico por imagem , Porosidade , Rubus/química
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