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1.
J Photochem Photobiol B ; 200: 111641, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31677421

RESUMO

In the current study, we investigated transmission spectrum of the intermediate filaments (IFs) extracted from porcine retinal Müller cells (MC). The recorded transmission spectrum is quite similar to that of the entire guinea pig retina, providing direct proof that the quantum mechanism (QM) of light energy transmission through the inverted retina is in fact the main mechanism determining the high-contrast vision of the vertebrate eyes. The recorded transmission spectrum of the IFs was deconvoluted into four bands, which we assign to different types of IFs. We interpret the differences in the transmission band shape and maxima as differences in the effective electron mass, dependent on the IF structure and composition of its constituting proteins. We analyzed model systems containing IFs and dye molecules, and IFs bridging two adjacent cobalt nanofilms on a substrate. The respective results demonstrate that IFs function as waveguides transferring energy from an energy donor and to an energy acceptor, by way of the exchange mechanism. The presently reported results provide direct experimental confirmation of the earlier proposed quantum mechanism for the high-contrast vision of vertebrate eyes. The mechanism proposed in the current study may be generalized, providing a consistent alternative to Davydov's theory of vibrational solitons in enzymes.


Assuntos
Filamentos Intermediários/química , Luz , Animais , Corantes/química , Transferência de Energia , Células Ependimogliais/citologia , Células Ependimogliais/metabolismo , Cobaias , Filamentos Intermediários/efeitos da radiação , Teoria Quântica , Retina/citologia , Suínos
2.
J Photochem Photobiol B ; 201: 111649, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31710925

RESUMO

In the present systematic study, silver nanoparticles have been synthesized using the fruits of Alpinia nigra. Apart from the presence of saponins, glycosides, alkaloids, steroids, the extract of A. nigra fruits are rich in polyphenols. The Total Flavonoid and Phenol Content of A. nigra fruits extract is 718 mgRE/g extract and 74.9 mgGAE/g extract respectively. The formation of the nanoparticles was validated through characterization techniques like UV-Vis spectroscopy, X- ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Energy dispersive X-ray spectroscopy (EDX). The spherical shape of silver nanoparticles is observed in Transmission Electron Microscopy (TEM) images. The average particle size of the silver nanoparticles is 6 nm. The biomolecules of the fruit extract played the dual role of reducing and capping agents which is evident from Fourier Transform Infrared (FTIR) spectrometer and Scanning Electron Microscopy (SEM) image analysis. The A. nigra capped silver nanoparticles exhibited promising antimicrobial activity against gram negative bacteria Klebsiella pneumoniae, gram positive bacteria Staphylococcus aureus and the pathogenic fungus, Candida albicans. Amongst the three pathogens, Klebsiella pneumoniae is the most susceptible to silver nanoparticles. Furthermore, the nanoparticles efficiently catalysed the degradation of the anthropogenic dyes Methyl orange, Rhodamine B and Orange G in the presence of sunlight. The photocatalytic degradation process follows the pseudo-first order kinetics. These results confirm that the silver nanoparticles can be efficiently synthesized via a green route using A. nigra fruits with applications as antimicrobial and catalytic agents.


Assuntos
Alpinia/química , Anti-Infecciosos/síntese química , Nanopartículas Metálicas/química , Prata/química , Alpinia/metabolismo , Anti-Infecciosos/farmacologia , Compostos Azo/química , Catálise , Corantes/química , Frutas/química , Frutas/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Nanopartículas Metálicas/toxicidade , Tamanho da Partícula , Extratos Vegetais/química , Luz Solar
3.
J Photochem Photobiol B ; 200: 111631, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31630045

RESUMO

In this work, over the course of four seasons (12 months), we have monitored the fluorescence quantum efficiency (η) from two sets (S1 and S2) of fresh natural dye extracts from the leaves of Tradescantia pallida purpurea. The natural dye was extracted in aqueous solutions from leaves collected from regions with a predominance of shade (S1) and sun (S2) during the day. The thermo-optical parameter fractional thermal load (φ) was measured using conical diffraction (CD) patterns caused by thermally driven self-phase modulation, for η determination in both sets of solutions. Fluorescence measurements corroborate the CD results, and the η values are, on average, slightly higher (~ 11%) in the summer than in the other seasons for both sets of samples (S1 and S2). In addition, the experimental results are presented using natural dye extracted from Tradescantia pallida purpurea as a fungicide probe in Fusarium solani, Sclerotinia sclerotiorum, and Colletotrichum gloeosporioides fungi. The promising fungicide results obtained for the aqueous natural dye extract were compared with those obtained for other natural dyes and fungi. The fungi tested are of the necrotrophic group and constitute important pathosystems in Brazil, causing diseases in several crops that synthetic fungicides often cannot control or do so with low efficiency.


Assuntos
Antifúngicos/química , Corantes/química , Extratos Vegetais/química , Tradescantia/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Corantes/isolamento & purificação , Corantes/farmacologia , Fungos/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/metabolismo , Refratometria , Estações do Ano , Tradescantia/metabolismo
4.
Chemosphere ; 235: 1189-1196, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561310

RESUMO

A high oxygen evolution potential (2.6V) and conductivity of Ti/TiO2 NTs/Ta2O5-PbO2 anode was fabricated by mixed metal oxide. A well-aligned TiO2 nanotubes was successfully prepared by using 1-butyl-3-methylimidazolium tetrafluoroborate as the electrolyte. The surface structure of anodes were characterized by scanning electron microscope, X-ray diffraction and energy dispersive X-ray spectroscopy. During the electrochemical degradation experiments, the effects of different anodes, current density, initial pH value and concentration were discussed. The results showed that co-doped Ta2O5 coating is an effective method to improve the surface morphology and the electrochemical characterization of Ti/TiO2 NTs/PbO2. At the initial pH value of 3 and current density of 12 mA cm-2, the removal rates of Acid Orange 7 and total organic carbon with Ti/TiO2 NTs/Ta2O5-PbO2 anode were almost 100% and 98.3%. Comparing with Ti/PbO2 anode at the same charge consumption (3 A h L-1), the instantaneous current efficiency of the Ti/TiO2 NTs/Ta2O5-PbO2 anode and Ti/TiO2 NTs/PbO2 anode increased by 40.0% and 27.1%, respectively. The highest rate of k.OH on Ti/TiO2 NTs/Ta2O5-PbO2 anode was 12.4 µmol (L min)-1. The organic dyes are oxidized into CO2 and H2O by .OH radical. The reaction process and mechanism during the electrochemical degradation were discussed.


Assuntos
Corantes/química , Técnicas Eletroquímicas/métodos , Nanotubos/química , Titânio/química , Compostos Azo , Benzenossulfonatos , Eletrodos , Oxirredução , Óxidos/química
5.
Water Sci Technol ; 80(1): 134-143, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31461430

RESUMO

The aim of this article was to clarify which type of dye chromophores could be decolorized efficiently with the use of laccase enzyme. For this purpose, enzymatic degradation of different type of dye classes (4 reactive, 2 acid and 1 basic dye) having various chromophore groups was investigated by using commercial laccase from Cerrena unicolor. It was observed that the chromophore structure of dye is very important on enzymatic color removal efficiency. According to the experimental results, it was found that color removal efficiencies (20 mg/L initial dye) were 98.7% for RB220 (0.1 g/L enzyme after 6 h), 95.1% for RB19 (0.1 g/L enzyme after 48 h), 90.8% for AR42 (0.1 g/L enzyme after 48 h) while they were 60.9% for AR114 (0.25 g/L enzyme), 58.6% for RB21 (0.5 g/L enzyme), 39.7% for RR239 (0.25 g/L enzyme) even after seven days. As a result, it can be said that the highest decolorization rate was achieved for the reactive dye having formazan copper complex (RB220) chromophore. On the other hand, the enzymatic degradation of basic dye (BB9) was found to be rather difficult compared to the acid and reactive dyes used in this study and the maximum color removal was 42.8% after seven days.


Assuntos
Corantes/análise , Lacase/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Cor , Corantes/química , Cobre , Poluentes Químicos da Água/química
6.
Sci Total Environ ; 685: 847-855, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390714

RESUMO

A low-cost and well-separated approach is introduced for adsorption pollutants in water. Chemical modified lignin is prepared with diethylenetriamine to enhance the reaction activities, then used to prepare lignin derivate magnetic hydrogel microspheres (LDMHMs) via blending with Fe3O4. The LDMHMs are successful prepared by the determination of FT-IR data, and the morphology shown from SEM imagine indicates the LDMHMs are in nanosized. The prepared LDMHMs are used as adsorbents for organic dyes, such as methylene blue (MB), methyl orange (MO) and malachite green (MG), the plateaus data are 43 mg/g, 39 mg/g and 155 mg/g, respectively. For inorganic pollutions, such as Pb2+, Hg2+ and Ni2+, the plateaus data are 33 mg/g, 55 mg/g and 23 mg/g, respectively. The adsorption data of unmodified lignin are 2.6 mg/g (Pb2+), 3.3 mg/g (Hg2+), 2.1 mg/g (Ni2+), 8 mg/g (MB), 10 mg/g (MG) and 2 mg/g (MO) in the same condition. The adsorbents are recycled by magnetic separation, regenerating from acid condition and reused for multiple cycles. The regeneration ratios are all above 90%, indicating a highly reusability and further reducing the cost of the treatment.


Assuntos
Corantes/química , Hidrogéis/química , Lignina/química , Microesferas , Poluentes Químicos da Água/química , Purificação da Água/métodos
7.
Environ Pollut ; 253: 1056-1065, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31434183

RESUMO

Synthetic dyes are toxic and carcinogenic in nature, which also causes environmental pollution. The present study was aimed to decolorize various commercial dyes using purified recombinant bacterial laccases. Laccase gene from Yersinia enterocolitica strain 8081 (yacK), Y. enterocolitica strain 7 (yacK) and Bacillus pumilus DSKK1 was cloned in vector pET28a and overproduced in host Escherichia coli BL21. The high yield of recombinant laccase protein resulted in the formation of inclusion bodies, which were further solubilized, refolded, and purified. The purified recombinant laccases were alkali-tolerant and thermostable, with pH optima at 7-8, temperature optima at 60-70 °C and low redox potential. For in silico studies, laccase protein models of B. pumilus DSKK1, Y. enterocolitica strain 7 and Y. enterocolitica strain 8081 were docked with commercial dyes. This is the first and foremost study where the stability of docked complexes of pathogenic and non-pathogenic microorganism has been explored via molecular dynamics (MD) simulations using Gromacs version 4.5.5 with the gromos96 43a force field. Finally, the in silico results were validated experimentally and it was found that purified laccases from B. pumilus DSKK1 and Y. enterocolitica strain 7 efficiently decolorized rose bengal (90.4%), malachite green (77.7%), and congo red (74.5%) dyes.


Assuntos
Corantes/química , Lacase/química , Simulação de Dinâmica Molecular , Poluentes Químicos da Água/química , Biodegradação Ambiental , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Lacase/metabolismo , Modelos Químicos , Oxirredução , Corantes de Rosanilina , Temperatura Ambiente , Poluentes Químicos da Água/metabolismo
8.
J Phys Chem Lett ; 10(18): 5422-5427, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31469573

RESUMO

Bacteriorhodopsin is a prototypical photoreceptor protein that functions as a light-driven proton pump. The retinal chromophore of bacteriorhodopsin undergoes C13═C14 trans-to-cis isomerization upon photoexcitation, and it has been believed to be the first event that triggers the cascaded structural changes in bacteriorhodopsin. We investigated the protein dynamics of bacteriorhodopsin using deep-ultraviolet resonance femtosecond stimulated Raman spectroscopy. It was found that the stimulated Raman signals of tryptophan and tyrosine residues exhibit significant changes within 0.2 ps after photoexcitation while they do not noticeably change during the isomerization process. This result implies that the protein environment changes first, and its change is small during isomerization. The obtained femtosecond stimulated Raman data indicate that ultrafast change is induced in the protein part by the sudden creation of the large dipole of the excited-state chromophore, providing an environment that realizes efficient and selective isomerization.


Assuntos
Bacteriorodopsinas/química , Corantes/química , Processos Fotoquímicos , Retina/química , Análise Espectral Raman/métodos , Cinética , Conformação Proteica , Estereoisomerismo , Triptofano/química , Tirosina/química , Raios Ultravioleta
9.
Chem Commun (Camb) ; 55(67): 9967-9970, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31367705

RESUMO

Herein, a seesaw ratiometric (SR) probe is designed which integrates fluorescence and surface enhanced Raman scattering (SERS) technology. Fluorescence imaging enables tracking of the spatiotemporal dynamic behaviour of telomerase. Meanwhile, SERS reverse ratiometric measurement can enable sensitive detection of telomerase activity in single living cells.


Assuntos
Corantes/química , Imagem Óptica/métodos , Análise de Célula Única/métodos , Análise Espectral Raman/métodos , Telomerase/metabolismo , DNA/química , Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Humanos , Células MCF-7 , Nanopartículas Metálicas/química
10.
Chem Commun (Camb) ; 55(71): 10603-10606, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31424058

RESUMO

A truly ratiometric homogeneous electrochemical biosensor has been developed for sensitive miRNA detection based on the unique diffusion/intercalation properties of electroactive dyes without the need for electrode modification or materials preparation.


Assuntos
Técnicas Biossensoriais/métodos , Corantes/química , Técnicas Eletroquímicas/métodos , Substâncias Intercalantes/química , MicroRNAs/análise , DNA/química , Eletrodos , Exodesoxirribonucleases/química , Compostos Ferrosos/química , Limite de Detecção , Metalocenos/química , Azul de Metileno/química , Oxirredução
11.
Ecotoxicol Environ Saf ; 182: 109396, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31276888

RESUMO

We report herein the sonochemical synthesis of a lanthanum dioxide carbonate (La2O2CO3) and zinc ferrite (ZnFe2O4)-loaded reduced graphene oxide (LZF-rGO) nanoheterostructure for ultrasound (US)-assisted degradation of methyl orange (MO) from water. The MO was chosen as a model organic dye due to its toxicological and biodegradable-resistant properties. The LZF-rGO catalyst was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results of characterizations confirmed successful synthesis of sonocatalyst. Among different removal systems, US/LZF-rGO displayed outstanding sonodegradation performance for degradation of MO. The maximum removal efficiency of 75.9% was achieved using 0.2 g/L sonocatalyst, 20 mg/L MO, and 0.71 W/cm2 US power intensity for 65 min. MO can be partially adsorbed on LZF-rGO but mostly sonodegraded by reactive radical species. The reaction conditions were optimized by investigating the effect of key operating parameters, including the sonocatalyst dosage, initial MO concentration, US power intensity, presence of inorganic salts, and use of an enhancer, on the decolorization of MO. The degradation intermediates produced from MO during the sonocatalytic process were identified by UPLC®/MS-MS, and possible mechanism and pathway for the degradation of MO in the US/LZF-rGO system were also proposed. Reusability experiments with this sonocatalyst revealed a less than 10% drop in the degradation efficiency after four adsorption-desorption cycles.


Assuntos
Corantes/química , Grafite/química , Lantânio/química , Nanoestruturas/química , Poluentes Químicos da Água/química , Carbonatos , Catálise , Compostos Férricos , Magnetismo , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Modelos Químicos , Óxidos/química , Espectroscopia Fotoeletrônica , Água , Difração de Raios X , Zinco , Compostos de Zinco , Óxido de Zinco/química
12.
Chemistry ; 25(54): 12601-12610, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31291028

RESUMO

Polymer micelles are an attractive means to solubilize water insoluble compounds such as drugs. Drug loading, formulations stability and control over drug release are crucial factors for drug-loaded polymer micelles. The interactions between the polymeric host and the guest molecules are considered critical to control these factors but typically barely understood. Here, we compare two isomeric polymer micelles, one of which enables ultra-high curcumin loading exceeding 50 wt.%, while the other allows a drug loading of only 25 wt.%. In the low capacity micelles, steady-state fluorescence revealed a very unusual feature of curcumin fluorescence, a high energy emission at 510 nm. Time-resolved fluorescence upconversion showed that the fluorescence life time of the corresponding species is too short in the high-capacity micelles, preventing an observable emission in steady-state. Therefore, contrary to common perception, stronger interactions between host and guest can be detrimental to the drug loading in polymer micelles.


Assuntos
Antineoplásicos/química , Corantes/química , Curcumina/química , Portadores de Fármacos/química , Micelas , Polímeros/química , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cinética , Luz , Tamanho da Partícula , Solubilidade , Espectrometria de Fluorescência , Temperatura Ambiente
13.
Environ Sci Pollut Res Int ; 26(26): 26869-26882, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31302892

RESUMO

The degradation of organic contaminants in actual textile wastewater was carried out by iron carbon (Fe-C) micro-electrolysis. Different Fe-C micro-electrolysis systems (SIPA and SISA) were established by using scrap iron particle (SIP) and scrap iron shaving (SIS) as anode materials. The optimal condition of both systems was obtained at the initial pH of 3.0, dosage of 30 g/L and Fe/C mass ratio of 1:1. Commercial spherical Fe-C micro-electrolysis material (SFC) was used for comparison under the same condition. The results indicated that total organic carbon (TOC) and chroma removal efficiencies of SIPA and SISA were superior to that of SFC. Total iron concentration in solution and XRD analysis of electrode materials revealed that the former showed relatively high iron corrosion intensity and the physicochemical properties of scrap iron indeed affected the treatment capability. The UV-vis and 3DEEM analysis suggested that the pollutants degradation was mainly attributed to the combination of reduction and oxidation. Furthermore, the potential degradation pathways of actual textile wastewater were illustrated through the GC-MS analysis. Massive dyes, aliphatic acids, and textile auxiliaries were effectively degraded, and the SIPA and SISA exhibited higher performance on the degradation of benzene ring and dechlorination than that by SFC. In addition, SIPA and SISA exhibited high stability and excellent reusability at low cost. Graphical abstract.


Assuntos
Eletrodos , Eletrólise/métodos , Ferro/química , Indústria Têxtil , Eliminação de Resíduos Líquidos/métodos , Carbono/química , Corantes/química , Custos e Análise de Custo , Eletrólise/economia , Eletrólise/instrumentação , Concentração de Íons de Hidrogênio , Oxirredução , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/química , Poluentes Químicos da Água/química , Difração de Raios X
14.
Phys Chem Chem Phys ; 21(31): 17163-17169, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31342023

RESUMO

Two-dimensional (2D) heteromaterials with large interface contact and intimate interfacial charge transition have been considered to be an ideal model for constructing highly efficient photocatalysts. However, few studies have reported on these 2D heterojunctions. Herein, we report a series of new 2D heterojunctions comprising polyimide (PI) and perylene-3,4,9,10-tetracarboxylic dianhydride (TD). These heterojunctions, denoted as PI-TDx (where x represents the amount of TD added, i.e., x = 0.13, 0.18, 0.27, 0.54, and 1.08 g), were prepared by the solid thermal copolymerization of melamine (MA), pyromellitic dianhydride (PD), and different amounts of TD. FT-IR spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy analyses were used to verify the 2D heterojunction structure. Photocatalytic experiments reveal that PI-TDx exhibit excellent and stable photocatalytic performance for the degradation of the organic dyes rhodamine B (RhB) and methyl violet (MV), as well as for the photoreduction of Cr(vi), under visible-light irradiation. Among the samples, PI-TD0.18 exhibits the best photocatalytic performance. Its activity is about 2.7 times and 7.5 times higher than that of individual PIMP (formed by MA and PD) and PIMT (formed by MA and TD) for RhB degradation, respectively. Notably, PI-TD0.18 retains a certain photocatalytic activity under light irradiation at 600 nm. The photocatalytic-mechanism study demonstrates that PI-TD0.18 has a classic type-II heterojunction. Its 2D heterojunction greatly enhances the visible-light absorption of the composites and effectively suppresses the radiation recombination of photogenerated carriers, thereby improving its charge transfer and separation abilities and providing excellent photocatalytic performance. This work may serve as an important reference for the design and construction of new highly efficient 2D organic conjugated-polymer photocatalysts.


Assuntos
Poluentes Ambientais/química , Perileno/análogos & derivados , Perileno/química , Resinas Sintéticas/química , Catálise , Cromo/química , Corantes/química , Violeta Genciana/química , Luz , Oxirredução , Processos Fotoquímicos , Rodaminas/química , Propriedades de Superfície
15.
Photochem Photobiol Sci ; 18(8): 2003-2011, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31268087

RESUMO

Here we report the activatable photosensitizer BromoAcroB, a brominated BODIPY dye incorporating a reactive acrolein warhead. The acrolein moiety serves as an intramolecular switch, deactivating the BODIPY dye in its singlet and triplet excited states via internal conversion. Thiolate addition to this moiety disables the intramolecular quenching mechanism restoring the photosensitizing properties of the parent dye, characterized by a quantum yield of singlet oxygen photosensitization of 0.69 ± 0.02. In cell cultures, and upon thiol adduct formation, BromoAcroB induced light-dependent cell death in MRC-5 and HeLa cell lines. Using fluorescence microscopy and upon measuring the low yet non-negligible emission of the activated compound, we show that the phototoxicity of the dormant photosensitizer correlated with the quantity of BromoAcroB adducts generated. BromoAcroB thus serves as a dormant photosensitizer sensitive to intracellular electrophile response. Our results highlight the effective control of a triplet state process by modulation of an unsaturated moiety on the BODIPY scaffold and underscore the mechanistic opportunities arising for controlled singlet oxygen production in cells specifically sensitive to electrophile stress.


Assuntos
Acroleína/farmacologia , Compostos de Boro/farmacologia , Corantes/farmacologia , Cisteína/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Oxigênio Singlete/farmacologia , Acroleína/química , Compostos de Boro/química , Morte Celular/efeitos dos fármacos , Corantes/síntese química , Corantes/química , Cisteína/química , Células HeLa , Humanos , Luz , Microscopia de Fluorescência , Estrutura Molecular , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Teoria Quântica , Oxigênio Singlete/química
16.
Photochem Photobiol Sci ; 18(8): 2012-2022, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31282525

RESUMO

Organic-metal complexes are promising molecules for use in photodynamic therapy (PDT). The aim of this study was to investigate in vitro effects of novel Ru(ii) and Ir(iii) BODIPY complexes for PDT. These hybrid organic-metal molecules (Ru-BD and Ir-BD) have been synthesized via reactions of a BODIPY precursor (BD) with a phenanthroline unit bearing Ru(ii) (3) and novel Ir(iii) (4) compounds. The crystal structures of the new distyryl BODIPY (BD) and Ru(ii) complex (3) are also reported. The photophysical and singlet oxygen generation properties of Ru-BD and Ir-BD were investigated in comparison with unsubstituted BODIPY (BD). Moreover, Ru-BD and Ir-BD have been biologically evaluated in vitro in chronic myeloid leukemia and cervical cancer cell lines in terms of photodynamic therapy efficacy in the presence of BD control. These complexes were not toxic in the dark but red light was needed to induce cell death. These data support the fact that Ru-BD could be accepted as a valuable photosensitizer-drug for further PDT treatment.


Assuntos
Antineoplásicos/farmacologia , Compostos de Boro/farmacologia , Corantes/farmacologia , Compostos Organometálicos/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Compostos de Boro/síntese química , Compostos de Boro/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Corantes/síntese química , Corantes/química , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Irídio/química , Irídio/farmacologia , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Rutênio/química , Rutênio/farmacologia , Oxigênio Singlete/análise , Oxigênio Singlete/metabolismo , Células Tumorais Cultivadas
17.
Photochem Photobiol Sci ; 18(8): 2023-2030, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31290525

RESUMO

Rising demands for renewable energy sources have led to the development of dye sensitized solar cells. It is a challenge to find a good and low cost sensitizer, which has a low environmental impact. In this work, we conducted spectroscopic and electrochemical experiments, as well as quantum-chemical calculations of the natural pigment hypericin, in order to provide insight into its sensitizing efficiency. To this end, three identical cells were made and characterized. Although this pigment exhibited good adsorption onto a semiconductor surface, a high molar absorption coefficient (43 700 L mol-1 cm-1) and favorable alignment of energy levels and provided a long lifetime of electrons (17.8 ms) in the TiO2 photoanode, it was found that the efficiency of hypericin-sensitized solar cells was very low, only 0.0245%. We suggest that this inefficiency originated from a low injection of electrons into the conduction band of TiO2. This conclusion is supported by the density functional theory calculations which revealed a low electron density in the anchoring groups of electronically excited hypericin. The results of this work could be valuable not only in the photovoltaic aspect, but also for application of hypericin in medicine in photodynamic therapy.


Assuntos
Corantes/química , Fontes de Energia Elétrica , Elétrons , Perileno/análogos & derivados , Energia Solar , Teoria da Densidade Funcional , Perileno/química , Titânio/química
18.
19.
Food Chem ; 298: 125014, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260973

RESUMO

Natural red purple dye, Betanin, was extracted from the beetroot, purified by aqueous two- phase extraction and gel permeation column chromatography, and used as a reducing agent for the synthesis of silver-betanin core-shell triangular nanodisks for the first time. Spectroscopic data show that the nanoparticle structure is core@shell like with Ag as core and betanin as shell. Langmuir monolayer model (qm = 32.4 mg/g, RL = 0.99 and R2 = 0.997) was the best fit adsorption isotherm for the dye removal. Adsorption kinetics is well explained by pseudo-second-order equation. Gibbs free energy (ΔG0 = -2.59 kJ mol-1), enthalpy (ΔH0 = 18.05 kJ mol-1), and entropy (ΔS0 = 68.92 J/K/mol) were calculated and discussed. The antibacterial activity of betanin-AgNPs were determined against Escherichia coli MTCC-450 (E. coli) and Staphylococcus aureus MTCC-3160 (S. aureus) bacteria.


Assuntos
Antibacterianos/farmacologia , Beta vulgaris/química , Betacianinas/farmacologia , Corantes/farmacologia , Nanopartículas Metálicas/química , Prata/química , Adsorção , Antibacterianos/química , Betacianinas/química , Betacianinas/isolamento & purificação , Corantes/química , Corantes/isolamento & purificação , Entropia , Escherichia coli/efeitos dos fármacos , Cinética , Staphylococcus aureus/efeitos dos fármacos , Termodinâmica
20.
Analyst ; 144(16): 4917-4924, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31313769

RESUMO

MicroRNAs (miRNAs) are attractive candidates for biomarkers for early cancer diagnosis, and play vital roles in physiological and pathological processes. In this work, we developed a colorimetric and fluorescent dual-mode sensor for miRNA detection based on the optical properties of gold nanoparticles (AuNPs) and the duplex-specific nuclease (DSN)-assisted signal amplification technique. In brief, FAM labelled hairpin probes (HPs) were immobilized on AuNPs, and fluorescence was efficiently quenched by the vicinity of the fluorophores to the AuNPs surface. In the presence of target miRNAs, the HPs could specifically hybridize with miRNAs and the DNA strand in the DNA/RNA heteroduplexes could be subsequently hydrolyzed by DSN. As a result, numbers of fluorophores were released into the solution, resulting in obvious fluorescence signal recovery. Meanwhile, the target miRNAs were able to participate in other hybridization reactions. With the DSN-assisted signal amplification technique, lots of gold nanoparticles were produced with short-chain DNA on their surface, which could aggregate in salt solution and result in a colorimetric detection. The proposed dual-mode strategy offers a sensitive, accurate and selective detection method for miRNAs. One reason is that the stem of the HPs was elaborately designed to avoid hydrolyzation by DSN under optimal conditions, which ensures a relatively low background and high sensitivity. The other is that the dual-mode strategy is more beneficial for enhancing the accuracy and reproducibility of the measurements. Moreover, the unique selective-cutting ability and single-base mismatch differentiation capability of the DSN also give rise to a satisfactory selectivity. This demonstrated that the developed method could quantitatively detect miR-21 down to 50 pM with a linear calibration range from 50 pM to 1 nM, and the analytical assay of target miRNAs in cell lysate samples revealed its great potential for application in biomedical research and clinical diagnostics.


Assuntos
Corantes/química , Endonucleases/química , Ouro/química , Nanopartículas Metálicas/química , MicroRNAs/análise , Técnicas Biossensoriais/métodos , Linhagem Celular , Colorimetria , DNA/química , Humanos , Limite de Detecção , Técnicas de Amplificação de Ácido Nucleico/métodos , Conformação de Ácido Nucleico , Ácidos Nucleicos Heteroduplexes/química , Hibridização de Ácido Nucleico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência
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