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1.
Anesth Analg ; 131(1): 288-297, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32543805

RESUMO

BACKGROUND: The inhalation anesthetics are potent greenhouse gases. To reduce the global environmental impact of the health care sector, technologies are sought to limit the release of waste anesthetic gas into the atmosphere. METHODS: Using a photochemical exhaust gas destruction system, removal efficiencies for nitrous oxide, desflurane, and sevoflurane were measured at various inlet concentrations (25% and 50%; 1.5%, 3.0%, and 6.0%; and 0.5%, 1.0%, and 2.0%, respectively) with flow rates ranging from 0.25 to 2.0 L/min. To evaluate the economic competitiveness of the anesthetic waste gas destruction system, its price per ton of carbon dioxide equivalent was calculated and compared to other greenhouse gas abatement technologies and current market prices. RESULTS: All inhaled anesthetics evaluated demonstrate enhanced removal efficiencies with decreasing flow rates (P < .0001). Depending on the anesthetic and its concentration, the photochemical exhaust gas destruction system exhibits a constant first-order removal rate, k. However, there was not a simple relation between the removal rate k and the species concentration. The costs for removing a ton of carbon dioxide equivalents are <$0.005 for desflurane, <$0.114 for sevoflurane, and <$49 for nitrous oxide. CONCLUSIONS: Based on this prototype study, destroying sevoflurane and desflurane with this photochemical anesthetic waste gas destruction system design is efficient and cost-effective. This is likely also true for other halogenated inhalational anesthetics such as isoflurane. Due to differing chemistry of nitrous oxide, modifications of this prototype photochemical reactor system are necessary to improve its removal efficiency for this gas.


Assuntos
Anestésicos Inalatórios/efeitos adversos , Anestésicos Inalatórios/química , Gases de Efeito Estufa/efeitos adversos , Gases de Efeito Estufa/química , Resíduos Perigosos/efeitos adversos , Fotoquímica/métodos , Anestesia por Inalação/efeitos adversos , Anestésicos Inalatórios/análise , Gases de Efeito Estufa/análise , Resíduos Perigosos/análise , Humanos
2.
Nat Commun ; 11(1): 2933, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32523065

RESUMO

Optical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of fluorescence in the biomedical field. NIR-II fluorescence enables deep-tissue imaging with micrometric resolution in animal models, but is limited by the low brightness of NIR-II probes, which prevents imaging at low excitation intensities and fluorophore concentrations. Here, we present a new generation of probes (Ag2S superdots) derived from chemically synthesized Ag2S dots, on which a protective shell is grown by femtosecond laser irradiation. This shell reduces the structural defects, causing an 80-fold enhancement of the quantum yield. PEGylated Ag2S superdots enable deep-tissue in vivo imaging at low excitation intensities (<10 mW cm-2) and doses (<0.5 mg kg-1), emerging as unrivaled contrast agents for NIR-II preclinical bioimaging. These results establish an approach for developing superbright NIR-II contrast agents based on the synergy between chemical synthesis and ultrafast laser processing.


Assuntos
Imagem Óptica/métodos , Fotoquímica/métodos , Corantes Fluorescentes , Nanopartículas/química , Pontos Quânticos
3.
Food Chem ; 322: 126778, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32305007

RESUMO

Zearalenone (ZEN) is highly toxic to humans, and therefore, development of sensitive and effective methods for ZEN quantification in cereal crops is particularly important. Here, an innovative photoelectrochemical (PEC) aptasensor based on simply in-situ conjugated composites of zinc oxide-nitrogen doped graphene quantum dots (ZnO-NGQDs) was constructed. On addition of NGQDs, the composites displayed higher PEC signal with 8.8-fold enhancement than pure ZnO nanoparticles. A sensitive and selective PEC aptasensor was fabricated by combining the composites with ZEN aptamer, which yielded an excellent analytical performance for ZEN detection, with a wide linear range of 1.0 × 10-13-1.0 × 10-7 g mL-1 and a low detection limit of 3.3 × 10-14 g mL-1. Good recoveries were obtained using the PEC aptasensor, which were consistent with those obtained using the national standard method (HPLC-MS). Finally, ZEN in mildewing cereal crops was monitored with the PEC aptasensor, exhibiting good potential for application in cereal crops for early diagnosis.


Assuntos
Aptâmeros de Nucleotídeos/química , Grão Comestível/química , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Fotoquímica/métodos , Zearalenona/análise , Grão Comestível/microbiologia , Farinha/análise , Farinha/microbiologia , Grafite/química , Limite de Detecção , Óxido Nítrico/química , Pontos Quânticos , Óxido de Zinco/química
4.
Chem Commun (Camb) ; 56(11): 1705-1708, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31942910

RESUMO

We report ultrathin organic photovoltaic elements optimized to run photofaradaic reactions in biological conditions. We demonstrate concurrent oxygen reduction to hydrogen peroxide and glucose oxidation. The devices are powered by deep-red irradiation in the tissue transparency window. We utilize bilayers of phthalocyanine, acting as the light absorber, and perylene diimide, functioning as both electron-acceptor and the hydrogen peroxide evolution electrocatalyst. These heterojunction bilayers are stable when irradiated in simulated physiological conditions, producing photovoltages sufficient to simultaneously drive cathodic oxygen reduction to H2O2 and anodic oxidation of glucose. We find that optimization of the anode metal is critical for sustained photofaradaic reactivity. Our results demonstrate a robust "wet" thin film photovoltaic with potential for physiological applications where localized electrochemical manipulation is desired, in particular the delivery of reactive oxygen species.


Assuntos
Técnicas Eletroquímicas/métodos , Peróxido de Hidrogênio/síntese química , Imidas/química , Indóis/química , Perileno/análogos & derivados , Técnicas Eletroquímicas/instrumentação , Desenho de Equipamento , Glucose/química , Ouro/química , Imidas/efeitos da radiação , Indóis/efeitos da radiação , Luz , Membranas Artificiais , Oxirredução , Oxigênio/química , Perileno/química , Perileno/efeitos da radiação , Fotoquímica/métodos
6.
Chemosphere ; 241: 124927, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31590029

RESUMO

Plasma treated g-C3N4 (PT-g-C3N4) was obtained by a simple and rapid DBD plasma modification process on the pristine g-C3N4. Compared with the pristine g-C3N4, the grain size of the PT-g-C3N4 decreased from 99.2 nm to 57.2 nm, the specific surface area and the pore volume increased by 15% and 33.8%, respectively. Oxygen-containing groups such as -NO2 and -COOH were observed to form on the surface of PT-g-C3N4 so the hydrophilic property of PT-g-C3N4 was much higher than that of pristine g-C3N4. More importantly, the photocatalytic H2O2 production activity of PT-g-C3N4 was significantly improved on account of the treatment in plasma atmosphere for only 5 min, the H2O2 yield of which was about 13 times that of the pristine g-C3N4. Our finding is not only of great significance for effectively promoting the production of H2O2 under mild conditions, but also proposes an innovative DBD plasma method to modify the g-C3N4 photocatalyst, which effectively promotes the improvement of photocatalytic activity and provides valuable insights for catalyst modification studies.


Assuntos
Grafite/química , Peróxido de Hidrogênio/química , Compostos de Nitrogênio/química , Catálise , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Fotoquímica/métodos , Porosidade , Propriedades de Superfície
7.
Talanta ; 206: 120242, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514896

RESUMO

High performance liquid chromatography (HPLC) post-column photochemical reaction (PR) coupled capacitively coupled contactless conductivity detector (C4D) was used for the first time in analysis of weak ultraviolet (UV)-absorbing, non-fluorescence and nonpolar compound. A series of conditions including the radiation power of light source, the length of the reaction tube and the thickness of detection tube were investigated. HPLC-PR-C4D system was successfully applied to the determination of Cyclosporin A (CsA). Consequently, under optimal conditions, the detection system exhibited a detection limit of 0.04 µg/mL and wide linear range from 0.5 µg/mL to 100 µg/mL for CsA detection. Application of the HPLC-PR- C4D system to pharmaceutical formulation and biological samples revealed the system developed maybe reliably applied to clinical studies.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ciclosporina/sangue , Fotoquímica/métodos , Cromatografia Líquida de Alta Pressão/instrumentação , Ciclosporina/efeitos da radiação , Humanos , Imunossupressores/sangue , Imunossupressores/efeitos da radiação , Limite de Detecção , Fotoquímica/instrumentação
8.
Chemosphere ; 239: 124766, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31527001

RESUMO

Iron (Fe)-doped ZrO2 tetragonal nanoparticles were synthesized by a facile and inexpensive hydrothermal technique, that were doped with Fe3+ ions (0.1, 0.3, and 0.5 mol%) into the host lattice without altering the morphology and crystal structure of the nanoparticles. SEM and TEM investigations indicated that the morphology of ZrO2 nanoparticles did not change even after incorporation of Fe, while the band gap of semiconducting ZrO2 nanoparticles was reduced from 4.97 to 1.77 eV. Such a in band gap was responsible to harvest more photons to stimulate the generation of more electrons in the valence band, thereby enhancing the photoelectrochemical (PEC) water splitting as well as photocatalytic and photoelectrocatalytic activities in the photodegradation of Rhodamine B. The 0.3 mol%-doped ZrO2 electrode showed enhanced photocurrent density (0.07 × 10-3 A/cm2), that was 45-times greater than the pure sample. The electrochemical impedance spectroscopy (EIS) confirmed that 0.3 mol%-doped ZrO2 exhibited the best charge transfer characteristics, which increased with PEC water splitting activity. The maximum photocurrent density and long-term photo-stability were achieved in the light on-off states.


Assuntos
Corantes/isolamento & purificação , Ferro/química , Nanopartículas Metálicas/química , Rodaminas/isolamento & purificação , Zircônio/química , Catálise , Corantes/química , Eletrodos , Poluentes Ambientais/química , Poluentes Ambientais/isolamento & purificação , Fotoquímica/instrumentação , Fotoquímica/métodos , Fotólise , Pontos Quânticos/química , Rodaminas/química , Água/química
9.
Biochim Biophys Acta Gen Subj ; 1864(2): 129317, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30851405

RESUMO

BACKGROUND: Proteins, which comprise one of the major classes of biomolecules that constitute a cell, interact with other cellular factors during both their biogenesis and functional states. Studying not only static but also transient interactions of proteins is important to understand their physiological roles and regulation mechanisms. However, only a limited number of methods are available to analyze the dynamic behaviors of proteins at the molecular level in a living cell. The site-directed in vivo photo-cross-linking approach is an elegant technique to capture protein interactions with high spatial resolution in a living cell. SCOPE OF REVIEW: Here, we review the in vivo photo-cross-linking approach including its recent applications and the potential problems to be considered. We also introduce a new in vivo photo-cross-linking-based technique (PiXie) to study protein dynamics with high spatiotemporal resolution. MAJOR CONCLUSIONS: In vivo photo-cross-linking enables us to capture weak/transient protein interactions with high spatial resolution, and allows for identification of interacting factors. Moreover, the PiXie approach can be used to monitor rapid folding/assembly processes of proteins in living cells. GENERAL SIGNIFICANCE: In vivo photo-cross-linking is a simple method that has been used to analyze the dynamic interactions of many cellular proteins. Originally developed in Escherichia coli, this system has been extended to studies in various organisms, making it a fundamental technique for investigating dynamic protein interactions in many cellular processes. This article is part of a Special issue entitled "Novel major techniques for visualizing 'live' protein molecules" edited by Dr. Daisuke Kohda.


Assuntos
Fotoquímica/métodos , Mapeamento de Interação de Proteínas/métodos , Animais , Benzofenonas/química , Células CHO , Códon , Cricetulus , Escherichia coli/metabolismo , Transferência Ressonante de Energia de Fluorescência , Células HEK293 , Humanos , Espectrometria de Massas , Methanocaldococcus/metabolismo , Fenilalanina/análogos & derivados , Fenilalanina/química , Estrutura Secundária de Proteína
10.
Biochim Biophys Acta Gen Subj ; 1864(2): 129362, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31078674

RESUMO

BACKGROUND: Single-molecule fluorescence imaging (smFI) has evolved into a valuable method used in biophysical and biochemical studies as it can observe the real-time behavior of individual protein molecules, enabling understanding of their detailed dynamic features. smFI is also closely related to other state-of-the-art microscopic methods, optics, and nanomaterials in that smFI and these technologies have developed synergistically. SCOPE OF REVIEW: This paper provides an overview of the recently developed single-molecule fluorescence microscopy methods, focusing on critical techniques employed in higher-precision measurements in vitro and fluorescent nanodiamond, an emerging promising fluorophore that will improve single-molecule fluorescence microscopy. MAJOR CONCLUSIONS: smFI will continue to improve regarding the photostability of fluorophores and will develop via combination with other techniques based on nanofabrication, single-molecule manipulation, and so on. GENERAL SIGNIFICANCE: Quantitative, high-resolution single-molecule studies will help establish an understanding of protein dynamics and complex biomolecular systems.


Assuntos
DNA/química , Microscopia de Fluorescência/métodos , Nanodiamantes/química , Nanotecnologia/métodos , Imagem Individual de Molécula/métodos , Fluorescência , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/química , Humanos , Cinética , Lipídeos/química , Microscopia Confocal , Nanoestruturas , Fotodegradação , Fotoquímica/métodos , Conformação Proteica , Pontos Quânticos , Propriedades de Superfície
11.
Proc Natl Acad Sci U S A ; 117(1): 135-140, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31852819

RESUMO

Redox enzymes are capable of catalyzing a vast array of useful reactions, but they require redox partners that donate or accept electrons. Semiconductor nanocrystals provide a mechanism to convert absorbed photon energy into redox equivalents for enzyme catalysis. Here, we describe a system for photochemical carbon-carbon bond formation to make 2-oxoglutarate by coupling CO2 with a succinyl group. Photoexcited electrons from cadmium sulfide nanorods (CdS NRs) transfer to 2-oxoglutarate:ferredoxin oxidoreductase from Magnetococcus marinus MC-1 (MmOGOR), which catalyzes a carbon-carbon bond formation reaction. We thereby decouple MmOGOR from its native role in the reductive tricarboxylic acid cycle and drive it directly with light. We examine the dependence of 2-oxoglutarate formation on a variety of factors and, using ultrafast transient absorption spectroscopy, elucidate the critical role of electron transfer (ET) from CdS NRs to MmOGOR. We find that the efficiency of this ET depends strongly on whether the succinyl CoA (SCoA) cosubstrate is bound at the MmOGOR active site. We hypothesize that the conformational changes due to SCoA binding impact the CdS NR-MmOGOR interaction in a manner that decreases ET efficiency compared to the enzyme with no cosubstrate bound. Our work reveals structural considerations for the nano-bio interfaces involved in light-driven enzyme catalysis and points to the competing factors of enzyme catalysis and ET efficiency that may arise when complex enzyme reactions are driven by artificial light absorbers.


Assuntos
Compostos de Cádmio/química , Dióxido de Carbono/metabolismo , Carbono/química , Luz , Nanotubos/química , Oxirredutases/metabolismo , Fotoquímica/métodos , Sulfetos/química , Acil Coenzima A , Alphaproteobacteria/enzimologia , Catálise , Ciclo do Ácido Cítrico , Transporte de Elétrons , Elétrons , Ferredoxinas/metabolismo , Cetoácidos , Ácidos Cetoglutáricos/metabolismo , Nanopartículas/química , Oxirredução
12.
Mater Sci Eng C Mater Biol Appl ; 107: 110334, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761214

RESUMO

Smart nanomaterials activated by light is one of the most exciting strategies to control the release of substances in varied environments. Here we developed a smart nanomaterial composed by a photoresponsive nanogel containing silver nanoparticles (AgNps) immobilized on the surface of biodegradable and biocompatible polycaprolactone (PCL) nanofibers mats produced by electrospinning. The AgNps are released from the nanogel and dispersed inside the nanofiber mats when this system is irradiated by light at 405 nm. This light excites the plasmonic band of the AgNps, which breaks the nanogel and, as a consequence, releases the AgNps on the nanofibers. Consequently, this AgNps release mechanism controls the propagation of silver ions by the application of light. Different configurations of antibacterial nanofibers mats, including neat PCL nanofibers and PCL nanofibers modified with AgNps-Nanogels and AgNps, excited by laser light at 405 nm, were investigated regarding antibacterial properties. The best result was achieved using PCL nanofiber mats functionalized with AgNps and AgNps-Nanogels after light exposure, which generated inhibition diameters of 2.6 ±â€¯0.3 mm and 1.8 ±â€¯0.5 mm for S. aureus and E. coli, respectively. The smart nanomaterial developed here is a promising material for clinical application as wound dressing activated by light.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Nanofibras/química , Fotoquímica/métodos , Antibacterianos/farmacocinética , Bandagens , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz , Escherichia coli/efeitos dos fármacos , Lasers , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Nanogéis , Poliésteres/química , Prata/química , Prata/farmacocinética , Staphylococcus aureus/efeitos dos fármacos
13.
Molecules ; 24(24)2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31817756

RESUMO

This work described a new sustainable method for the fabrication of ceramic membranes with high photocatalytic activity, through a simple sol-gel route. The photocatalytic surfaces, prepared at low temperature and under solvent-free conditions, exhibited a narrow pore size distribution and homogeneity without cracks. These surfaces have shown a highly efficient and reproducible behavior for the degradation of methylene blue. Given their characterization results, the microfiltration photocatalytic membranes produced in this study using solvent-free conditions are expected to effectively retain microorganisms, such as bacteria and fungi that could then be inactivated by photocatalysis.


Assuntos
Fotoquímica/métodos , Solventes/química , Catálise , Azul de Metileno/química , Temperatura
14.
Molecules ; 24(22)2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31726792

RESUMO

In this work, we present an automated luminescence sensor for the quantitation of the insecticide thiacloprid, one of the main neonicotinoids, in lettuce samples. A simple and automated manifold was constructed, using multicommutated solenoid valves to handle all solutions. The analyte was online irradiated with UV light to produce a highly fluorescent photoproduct (λexc/λem = 305/370 nm/nm) that was then retained on a solid support placed in the flow cell. In this way, the pre-concentration of the photoproduct was achieved in the detection area, increasing the sensitivity of the analytical method. A method-detection limit of 0.24 mg kg-1 was achieved in real samples, fulfilling the Maximum Residue Limit (MRL) of The European Union for thiacloprid in lettuce (1 mg kg-1). A sample throughput of eight samples per hour was obtained. Recovery experiments were carried out at values close to the MRL, obtaining recovery yields close to 100% and relative standard deviations lower than 5%. Hence, this method would be suitable for routine analyses in quality control, as an alternative to other existing methods.


Assuntos
Alface/química , Neonicotinoides/química , Compostos Fitoquímicos/química , Tiazinas/química , Concentração de Íons de Hidrogênio , Processos Fotoquímicos , Fotoquímica/métodos , Análise Espectral
15.
Anal Chim Acta ; 1090: 143-150, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31655639

RESUMO

A sandwich-type photoelectrochemical (PEC) immunosensor was constructed for sensitive detection of prostate specific antigen (PSA). It was based on electrochemically reduced graphene oxide-TiO2 (ERGO-TiO2) as photoelectrochemical platform to immobilize capture antibody (Ab1). Then, quinone-rich polydopamine nanospheres (PDANS) loaded detection antibody (Ab2) and photocurrent signal label, l-cysteine-coated cadmium sulfide quantum dots (CdSQDs). ERGO-TiO2 displayed greatly improved photocurrent response to white light. CdSQDs conjugated with PDANS further amplified photocurrent signal because of the good conductivity of PDANS and ERGO. The increased photocurrent showed a linear correlation with PSA in the concentration range from 0.02 pg mL-1 to 200 ng mL-1 with the detection limit of 6.8 fg mL-1. It also revealed high selectivity and good stability.


Assuntos
Compostos de Cádmio/química , Indóis/química , Nanosferas/química , Polímeros/química , Antígeno Prostático Específico/análise , Pontos Quânticos/química , Sulfetos/química , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Técnicas Biossensoriais/métodos , Cisteína/química , Técnicas Eletroquímicas/métodos , Feminino , Grafite/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Fotoquímica/métodos , Antígeno Prostático Específico/imunologia , Titânio/química
16.
Anal Chim Acta ; 1090: 64-71, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31655647

RESUMO

Using carcinoembryonic antigen (CEA) imprinted polymerized ionic liquid hydrogel as a recognition element and hollow gold nanoballs/MoSe2 nanosheets as a photoactive element, a photoelectrochemical (PEC) sensing platform was successfully fabricated. To accomplish the imprinted process under room temperature to maintain the biological activity and the configuration of CEA, and thus to improve the sensing performances, 3-{[{4-N,N-Bis[(carbamoyl)ethylmethacrylate]butyl}((carbamoyl)amino)ethyl methacrylate] -propyl}-1-ethenyl-1H-imidazol-3-ium bromide (BCCPEimBr) ionic liquid was synthesized. By using BCCPEimBr ionic liquid as the functional monomer, CEA as the template, a molecularly imprinted hydrogel film was prepared on a hollow gold nanoballs/MoSe2 nanosheets modified glassy carbon electrode surface. After removing the template, a CEA imprinted photoelectrochemical sensor was successfully fabricated. The imprinted PEC sensor shows good selectivity, sensitivity and stability towards CEA, produces a linear response in the concentration range from 0.05 to 5.0 ng mL-1 and shows a detection limit of 11.2 pg mL-1 (S/N = 3) under the optimized conditions. The imprinted PEC sensor was used to determine CEA in clinical human serum samples accurately. The procedure for the imprinted PEC sensing platform can be used for other biomolecules just by substituting the template.


Assuntos
Antígeno Carcinoembrionário/sangue , Hidrogéis/química , Líquidos Iônicos/química , Nanopartículas Metálicas/química , Nanocompostos/química , Polímeros/química , Técnicas Biossensoriais/métodos , Dissulfetos/química , Técnicas Eletroquímicas/métodos , Ouro/química , Ouro/efeitos da radiação , Humanos , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Impressão Molecular , Molibdênio/química , Fotoquímica/métodos , Reprodutibilidade dos Testes
17.
Mikrochim Acta ; 186(11): 692, 2019 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-31605242

RESUMO

A photocathode is described for the determination of microRNA-21 by using CuInS2 as an active photocathode material. Exonuclease III assisted target recycling amplification was employed to enhance the detection sensitivity. The TATA-binding protein (TBP) was applied to enhance steric hindrance which decreases the photoelectrochemical intensity. This strategy is designed by combining the anti-interference photocathode material, enzyme assisted target recycling amplification and TBP induced signal off, showing remarkable amplification efficiency. Under the optimized conditions, the detection limit for microRNA-21 is as low as 0.47 fM, and a linear range was got from 1.0 × 10-15 M to 1.0 × 10-6 M. Graphical abstract Schematic representation of sensitive photoelectrochemical detection of microRNA-21.CuInS2 is used as an active photocathode material. Combined Exonuclease III assisted target recycling amplification and TATA-binding protein decreased of photoelectrochemical intensity, the detection limit was 0.47 fM with good selectivity. (miR-21: microRNA-21; CS: chitosan).


Assuntos
DNA/química , Técnicas Eletroquímicas/métodos , Exodesoxirribonucleases/química , MicroRNAs/sangue , Fotoquímica/métodos , Sulfetos/química , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/química , Biomarcadores Tumorais/genética , Cobre/química , Cobre/efeitos da radiação , DNA/genética , Técnicas Eletroquímicas/instrumentação , Eletrodos , Humanos , Índio/química , Índio/efeitos da radiação , Sequências Repetidas Invertidas , Luz , Limite de Detecção , MicroRNAs/química , MicroRNAs/genética , Hibridização de Ácido Nucleico , Sulfetos/efeitos da radiação , Compostos de Estanho/química
18.
Analyst ; 144(21): 6193-6196, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31577279

RESUMO

We here describe a photocurrent generation system exploiting gold nanoparticles (AuNPs) that cover perylenediimide-DNA complexes on electrode surfaces. Enhanced photocurrents were generated by the irradiation of the AuNPs, attributed to the efficient excitation of the perylenediimides by a local electric field on the surface of the AuNPs.


Assuntos
DNA/química , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , Fotoquímica/métodos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Ouro/efeitos da radiação , Imidas/química , Imidas/efeitos da radiação , Luz , Nanopartículas Metálicas/efeitos da radiação , Perileno/análogos & derivados , Perileno/química , Perileno/efeitos da radiação
19.
Proc Natl Acad Sci U S A ; 116(39): 19449-19457, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31484780

RESUMO

Computational and biochemical studies implicate the blue-light sensor cryptochrome (CRY) as an endogenous light-dependent magnetosensor enabling migratory birds to navigate using the Earth's magnetic field. Validation of such a mechanism has been hampered by the absence of structures of vertebrate CRYs that have functional photochemistry. Here we present crystal structures of Columba livia (pigeon) CRY4 that reveal evolutionarily conserved modifications to a sequence of Trp residues (Trp-triad) required for CRY photoreduction. In ClCRY4, the Trp-triad chain is extended to include a fourth Trp (W369) and a Tyr (Y319) residue at the protein surface that imparts an unusually high quantum yield of photoreduction. These results are consistent with observations of night migratory behavior in animals at low light levels and could have implications for photochemical pathways allowing magnetosensing.


Assuntos
Columbidae/metabolismo , Criptocromos/química , Criptocromos/metabolismo , Sequência de Aminoácidos , Migração Animal/fisiologia , Animais , Luz , Campos Magnéticos , Fotoquímica/métodos , Relação Estrutura-Atividade , Vertebrados/metabolismo
20.
Molecules ; 24(18)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547232

RESUMO

Use of sonication for designing and fabricating reactors, especially the deposition of catalysts inside a microreactor, is a modern approach. There are many reports that prove that a microreactor is a better setup compared with batch reactors for carrying out catalytic reactions. Microreactors have better energy efficiency, reaction rate, safety, a much finer degree of process control, better molecular diffusion, and heat-transfer properties compared with the conventional batch reactor. The use of microreactors for photocatalytic reactions is also being considered to be the appropriate reactor configuration because of its improved irradiation profile, better light penetration through the entire reactor depth, and higher spatial illumination homogeneity. Ultrasound has been used efficiently for the synthesis of materials, degradation of organic compounds, and fuel production, among other applications. The recent increase in energy demands, as well as the stringent environmental stress due to pollution, have resulted in the need to develop green chemistry-based processes to generate and remove contaminants in a more environmentally friendly and cost-effective manner. It is possible to carry out the synthesis and deposition of catalysts inside the reactor using the ultrasound-promoted method in the microfluidic system. In addition, the synergistic effect generated by photocatalysis and sonochemistry in a microreactor can be used for the production of different chemicals, which have high value in the pharmaceutical and chemical industries. The current review highlights the use of both photocatalysis and sonochemistry for developing microreactors and their applications.


Assuntos
Fotoquímica/instrumentação , Sonicação/métodos , Catálise , Desenho de Equipamento , Microfluídica/instrumentação , Nanopartículas/química , Fotoquímica/métodos , Ultrassom/instrumentação , Ultrassom/métodos
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