RESUMO
Arbuscular mycorrhizal fungi (AMF) are often considered bioameliorators. AMF can promote plant growth under various stressful conditions; however, differences between male and female clones in mycorrhizal strategies that protect plants from the detrimental effects of salinity are not well studied. In this study, we aimed to examine the interactive effects of salinity and AMF on the growth, photosynthetic traits, nutrient uptake, and biochemical responses of Morus alba males and females. In a factorial setup, male and female M. alba clones were subjected to three salinity regimes (0, 50, and 200 mM NaCl) and planted in soil with or without Funneliformis mosseae inoculation. The results showed that NaCl alone conferred negative effects on the growth, salinity tolerance, photosynthetic performance, and shoot and root ionic ratios (K+/Na+, Ca2+/Na+, and Mg2+/Na+) in both sexes; in contrast, mycorrhizal inoculation mitigated the detrimental effects of salinity. Furthermore, the mycorrhizal effects were closely correlated with Mn2+, proline, and N concentrations. Females benefited more from AMF inoculation as shown by the enhancements in their biomass accumulation, and N, proline, K+, Mg2+, Fe2+, Zn2+, and Mn2+ concentrations than males with mycorrhizal inoculation under saline conditions. In comparison, male plants inoculated with AMF showed improvements in biomass allocated to the roots, P, and peroxidase concentrations under saline conditions. These sex-specific differences suggest that male and female mulberry clones adopted different mycorrhizal strategies when growing under saline conditions. Overall, our results provide insight into the sex-specific difference in the performance of AMF-associated mulberry clones, suggesting that female mulberry could be more suitable for vegetation remediation than the male one, due to its higher salinity tolerance.
RESUMO
[This corrects the article DOI: 10.1039/C9RA10312K.].
RESUMO
Sodium-ion capacitors (SICs) have shown great potential to combine the merits of high-power capability of traditional capacitors and high energy capability of batteries. However, the sluggish kinetics and inferior stability of conventional sodium-ion storage anode materials are major challenges for the practical utilization of SICs. In this work, interconnected urchin-like hollow Na2Ti3O7 (Na2Ti3O7-IcUH) chains were designed and prepared by a simple one-step template-assisting method. Through a variety of controlled experiments, we explored how to effectively engineer the crystal-oriented growth and string the urchin-like spheres together. Benefiting from its urchin-like hollow structure and fully exposed (001) facet, the resulting Na2Ti3O7-IcUH exhibits a superior rate capability of 96.2 mA h g-1 at 5 A g-1. Meanwhile, the interconnected three-dimensional primary structure endows Na2Ti3O7-IcUH with excellent cyclic stability (15% capacity loss at 5 A g-1 after 2000 cycles). By coupling with commercial active carbon, the assembled SIC successfully demonstrates a energy density of 134.3 W h kg-1 at a power density of 125 W kg-1 and 38.2 W h kg-1 at a high-power density of 2500 W kg-1, as well as a superior capacity retention of 75% after 2000 cycles at 2 A g-1 within 1-4 V.
RESUMO
Since the oxygen evolution catalysis process is vital yet arduous in energy conversion and storage devices, it is highly desirous but extremely challenging to engineer earth-abundant, noble-metal-free nanomaterials with superior electrocatalytic activity toward effective oxygen evolution reactions (OERs). Herein, we construct a prismlike cobalt-iron layered double hydroxide (Co-Fe LDH) with a Co/Fe ratio of 3:1 utilizing a facile self-templated strategy. Instead of carbon-species-coupled treatment, we focus on ameliorating the intrinsic properties of LDHs as OER electrocatalysts accompanied by the hierarchical nanoflake shell, well-defined interior cavity, and numerous microporous defects. In contrary to conventional LDHs synthesized via a one-pot method, Co-Fe LDHs fabricated in this work possess a huge specific surface area up to 294.1 m2 g-1, which not only provides abundant active sites but also expedites the kinetics of the OER process. The as-prepared Co-Fe LDH electrocatalysts exhibit advanced electrocatalytic performance and a dramatic stability of the OER in an alkaline environment. In particular, the contribution of micropore defects is clearly discussed according to the electrochemical impedance spectroscopy analysis, in which the time constant of the OER at the micropore defect is several orders of magnitude smaller than that at the exterior of Co-Fe LDHs, forcefully verifying the intrinsic catalytic activity enhancement derived from the micropore defects. This work provides a promising model to improve OER electrocatalyst activity via produce defects and research the contribution of micropore defects.
RESUMO
Monitoring superoxide anions in living cells have attracted much academic and biomedical interest due to their important role in metabolic processes. Herein, we confined ultra-small nano-Mn3(PO4)2 in chitosan and designed a unique puffy woven sphere consisted by nanowires. Further constructed an effective in situ detection chip using the as-synthesized nano-Mn3(PO4)2-chitosan for electrochemical sensing of superoxide anions from murine breast tumor cells (4T1). The excellent biocompatibility of chitosan and large size of the Mn3(PO4)2-chitosan spheres greatly reduced the damage and toxicity of the detection interface to the living cells, while the ultra-small nano-Mn3(PO4)2 in chitosan could effectively catalyze the superoxide anions released from cells. The nano-Mn3(PO4)2-chitosan-based sensor exhibited high sensitivity (1.6 µA µM-1), low detection limit (9.4â¯nM at S/Nâ¯=â¯3) and good selectivity for O2â¢-. After cell culture on the surface of nano-Mn3(PO4)2-chitosan based electrode. As a miniature analytical and sensing platform, results further suggest that the prepared chip offers a more sensitive detective superoxide anions (O2â¢-) released from 4T1 cell lines than traditional electron paramagnetic resonance (EPR) analysis.
Assuntos
Técnicas Biossensoriais , Quitosana/química , Técnicas Eletroquímicas , Superóxidos/isolamento & purificação , Enzimas Imobilizadas/química , Humanos , Manganês/química , Nanopartículas Metálicas/química , Superóxidos/químicaRESUMO
FePO4 is biocompatible and can act as a kind of promising enzyme mimetic. Unfortunately, the electrical conductivity of FePO4 is poor. In order to enhance its conductivity, FePO4 was embedded into nanofibers consisting of amorphous carbon and reduced graphene oxide (rGO) by an electrospinning technique. As a sensing material for monitoring superoxide anion (O2â¢-) and typically operated at 0.5 V (vs. SCE), it displays high sensitivity (9.6 µAâ µM-1â cm-2), a low detection limit (9.7 nM at S/N = 3), a wide linear response range (10 nM to 10 µM), and fast response (1.6 s). Due to its low detection limit and fast response, the sensor in our perception has a large potential for detecting superoxide anions released by HeLa cancer cells. Graphical abstract Schematic of the microstructure of FePO4/C and FePO4/rGO-C nanofibers, a photograph of cancer cells (HeLa), and the electrochemical response towards O2-⢠of the sensor.
Assuntos
Materiais Biomiméticos/química , Compostos Férricos/química , Grafite/química , Nanofibras/química , Superóxidos/química , Superóxidos/metabolismo , Sobrevivência Celular , Condutividade Elétrica , Eletroquímica , Células HeLa , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Limite de Detecção , OxirreduçãoRESUMO
Transition-metal phosphides (TMPs) have emerged as promising catalyst candidates for the hydrogen evolution reaction (HER). Although numerous methods have been investigated to obtain TMPs, most rely on traditional synthetic methods that produce materials that are inherently deficient with respect to electrical conductivity. An electrospinning-based reduction approach is presented, which generates nickel phosphide nanoparticles in N-doped porous carbon nanofibers (Ni2 P@NPCNFs) inâ situ. Ni2 P nanoparticles are protected from irreversible fusion and aggregation in subsequent high-temperature pyrolysis. The resistivity of Ni2 P@NPCNFs (5.34â Ω cm) is greatly decreased by 104 times compared to Ni2 P (>104 â Ω cm) because N-doped carbon NFs are incorporated. As an electrocatalyst for HER, Ni2 P@NPCNFs reveal remarkable performance compared to other previously reported catalysts in acidic media. Additionally, it offers excellent catalytic ability and durability in both neutral and basic media. Encouraged by the excellent electrocatalytic performance of Ni2 P@NPCNFs, a series of pea-like Mx P@NPCNFs, including Fe2 P@NPCNFs, Co2 P@NPCNFs, and Cu3 P@NPCNFs, were synthesized by the same method. Detailed characterization suggests that the newly developed method could render combinations of ultrafine metal phosphides with porous carbon accessible; thereby, extending opportunities in electrocatalytic applications.
RESUMO
In this work, we reported a novel and slack rose-like metal organic precursor designed by coordinating p-phenylenediamine with cobalt ion. After subsequent pyrolysis and acid etching process, the as-prepared Co-N-C catalyst delivered a superior catalytic activity and long-term durability. Further applied in the Zn-air battery, it also displayed a comparable performance with 20% Pt/C.
RESUMO
MicroRNA (miRNAs) quantification, especially at low abundance, is vital for disease diagnosis, prognosis, and therapy. Herein we develop a distinctive label-free "off-on" configuration for photoelectrochemical (PEC) sensing platform fabrication, coupled with DNA four-way junction (4J) architecture as well as G-wire superstructure for signal amplification. In addition, ultrathin copper phosphate nanosheets (CuPi NSs) coating Au nanoparticles (Au-CuPi NSs) serve as a highly efficient photocathode substrate. To improve the sensitivity, and avoid the false positive signals, the quencher, gold nanoparticles (GNPs), is utilized to switch off the PEC signal because of the commendable surface plasmon resonance (SPR) absorption. Subsequently, ingenious DNA 4J architecture is applied to export proportional c-myc regions for target quantification. Assisted with the G-wire superstructure formation, the enhancer 5,10,15,20-tetra(4-sulfophenyl)-21H,23H-porphyrin (TSPP) is coupled on the substrate to switch on the PEC signal, thus realizing the miRNA assay with persuasive accuracy, high sensitivity, and low detection limit. In addition, we execute the miRNA detection in prostate carcinoma cell line 22Rv1, and acquire desirable quantitative capability. Remarkably, the prepared PEC sensing platform not only realizes the highly efficient miRNAs quantification, but also uncovers a marvelous horizon for sensing platform fabrication.
Assuntos
MicroRNAs/análise , Nanotecnologia/instrumentação , Processos Fotoquímicos , Eletroquímica , Ouro/química , Células HeLa , Humanos , Nanopartículas Metálicas/química , Fosfatos/química , Porfirinas/química , Ressonância de Plasmônio de SuperfícieRESUMO
Metal-organic framework (MOF)-derived hollow cobalt sulfides have attracted extensive attention due to their porous shell that provides rich redox reactions for energy storage. However, their ultradispersed structure and the large size of MOF precursors result in relatively low conductivity, stability, and tap density. Therefore, the construction of an array of continuous hollow cages and tailoring of the inner cavity of MOF-derived materials is very effective for enhancing the electrochemical performance. Herein, we in situ assembled small Co-based zeolitic imidazolate framework (ZIF-67) on the both sides of negatively charged MnO2 nanosheets to fabricate a hierarchical sandwich-type composite with hollow cobalt sulfide nanocages/graphene-like MnO2. The graphene-like MnO2 nanosheets acted not only as a structure-directing agent to grow a ZIF-67 array but also as a promising electroactive material of electrochemical capacitors to provide capacitance. As an electrode material of supercapacitors, the as-prepared composites exhibit high specific capacitance (1635 F g-1 at 1 A g-1), great rate performance (reaching 1160 F g-1 at 10 A g-1), and excellent cycling stability (80% retention after 5000 cycles). The outstanding electrochemical properties of our designed materials can be attributed to the unique nanostructure that improved electrical conductivity, created more reactive active sites, and increased the diffusion pathway for electrolyte ions.
RESUMO
Herein, we focus on preparing a highly efficient photocatalytic material to construct a signal-on photoelectrochemical (PEC) sensing platform in view of the rigorous demand of accurate miRNA quantification. The well-dispersed Pt nanoclusters-coated copper phosphate ultrathin nanosheets (PtNCs/Cu3(PO4)2NSs) were first successfully synthesized as a photoelectrode material. Because of the ultrathin two-dimensional lamellar structure of Cu3(PO4)2NSs with a 1.3 nm thickness, as well as the homogeneous size and abundant PtNCs loaded on Cu3(PO4)2NSs, the resultant PtNCs/Cu3(PO4)2NSs were employed as a photoelectrode material for the first time and revealed outstanding photocatalytic activity in PEC sensing as a substrate. As a well-designed protocol, we realized accurate miRNA quantification via a novel signal amplification strategy based on G-wire superstructure exponentially ligating a signal probe, which possesses efficient and simple operation compared to the traditional amplification method. Moreover, the electron donor is generated in situ by lactate oxidase (Lox) labels catalyzing lactate for H2O2 production, boosting the efficient separation of electron-hole pairs for further signal amplification. Impressively, this PEC sensing platform is commendably utilized to determine miRNA-141 from prostate carcinoma cell line 22Rv1. This study, considering the excellent PtNCs/Cu3(PO4)2NSs combined with G-wire superstructure for exponential signal amplification strategy, paves a new path in biosensing and clinical diagnosis.
Assuntos
Técnicas Biossensoriais , Cobre , MicroRNAs/análise , Nanoestruturas , Platina , Linhagem Celular Tumoral , Técnicas Eletroquímicas , Humanos , Peróxido de Hidrogênio , Masculino , Neoplasias da PróstataRESUMO
Monitoring superoxide anion radicals in living cells has been attracting much academic and industrial interest due to the dual roles of the radicals. Herein, we synthesized a novel nanostructured cobalt phosphate nanorods (Co3(PO4)2 NRs) with tunable pore structure using a simple and effective micro-emulsion method and explored their potential utilization in the electrochemical sensing of superoxide anions. As an analytical and sensing platform, the nanoscale biomimetic enzymes Co3(PO4)2 NRs exhibited excellent selectivity and sensitivity towards superoxide anion (O2â¢-) with a low detection limit (2.25nM), wide linear range (5.76-5396nM), and long-term stability. Further, the nanoscale biomimetic enzyme could be efficiently applied in situ to electrochemically detect O2â¢- released from human malignant melanoma cells and normal keratinocyte, showing excellent real time quantitative detection capability. This material open up exciting opportunities for implementing biomimetic enzymes in nanoscale transition metal phosphates and designing enzyme-free biosensors with much higher sensitivity and durability in health and disease analysis than those of natural one.
Assuntos
Materiais Biomiméticos/química , Cobalto/química , Técnicas Eletroquímicas/métodos , Nanotubos/química , Fosfatos/química , Superóxidos/análise , Técnicas Biossensoriais/métodos , Catálise , Linhagem Celular , Humanos , Nanotubos/ultraestruturaRESUMO
The efficiency of photon-to-electron conversion is extremely restricted by the electron-hole recombinant. Here, a new photoelectrochemical (PEC) sensing platform has been established based on the signal amplification of click chemistry (CC) via hybridization chain reaction (HCR) for highly sensitive microRNA (miRNA) assay. In this proposal, a preferred electron donor dopamine (DA) was first assembled with designed ligation probe (probe-N3) via amidation reaction to achieve DA-coordinated signal probe (PDA-N3). The PDA-N3 served as a flexible trigger to signal amplification through efficiently suppressing the electron-hole recombinant. Specifically, the PDA-N3 can be successfully ligated into the trapped hairpins (H1 and H2) via the superior ligation method of metal-catalyst-free CC, in which the electron donor DA was introduced into the assay system. Moreover, the enzyme-free HCR, employed as a versatile amplification way, ensures that lots of PDA-N3 can be attached to the substrate. This PEC sensing for miRNA-141 detection illustrated the outstanding linear response to a concentration variation from 0.1 fM to 0.5 nM and a detection limit down to 27 aM, without additional electron donors. The sensor is further employed to monitor miRNA-141 from prostate carcinoma cell (22Rv1), showing good quantitative detection capability. This strategy exquisitely influences the analytical performance and offers a new PEC route to highly selective and sensitive detection of biological molecules.
Assuntos
Técnicas Biossensoriais , Bismuto/química , Dissulfetos/química , Dopamina/química , Técnicas Eletroquímicas , MicroRNAs/análise , Molibdênio/química , Neoplasias da Próstata/química , Sulfetos/química , Linhagem Celular Tumoral , Química Click , Células HeLa , Humanos , Masculino , Nanoestruturas/química , Técnicas de Amplificação de Ácido Nucleico , Tamanho da Partícula , Processos Fotoquímicos , Propriedades de SuperfícieRESUMO
In this communication, a novel platanus hispanica-like, highly integrated hierarchical electrocatalyst, with Co-carbon nanotubes anchored through porous Co embedded carbon sphere frameworks (Co-CNTFs), was fabricated using a chemical vapor deposition (CVD) method. More importantly, the prepared Co-CNTFs demonstrate even better activity than commercial Pt electrocatalysts in an alkaline medium. This presented CVD approach provides an effective way to grow metal-CNTs in situ through various metal-complex-derived functional nanomaterials and can be expanded to metallic oxide, metallic sulfide, and metallic phosphide, among others, to introduce carbon nanotube frameworks with a multitude of potential applications.
RESUMO
We report a general approach for the synthesis of yolk-shell-structured porous dicobalt phosphide/zinc oxide@porous carbon polyhedral/carbon nanotube hybrids (Co2P/ZnO@PC/CNTs) derived from bimetal-organic frameworks, and explore their potential utilization in the electrochemical sensing of superoxide anions. Beyond our expectation, the trace level of O2Ë- released from living cells has also been successfully captured by our designed sensor. The presented strategy for the controlled design and synthesis of bimetal-organic frameworks-derived functional nanomaterials offers prospects of developing highly active electrocatalysts in non-enzyme sensors.
RESUMO
In this communication, we designed and synthesized a novel calcium-organic framework and presented it as an anode material for sodium-ion batteries. The results show that it delivers a reversible capacity of higher than 140 mA h g(-1) even after 300 cycles. The remarkable performance is attributed to the high structural stability and extremely low solubility of the calcium-organic framework in electrolytes.
RESUMO
Electrochemical oxidation of glucose is the guarantee to realize nonenzymatic sensing of glucose, but greatly hindered by the slow kinetics of its oxidation process. Herein, various nanomaterials were designed as catalysts to accelerate glucose oxidation reaction. However, how to effectively build an excellent platform for promoting the glucose oxidation is still a great challenge. In our work, 1D CaMoO4 and NiMoO4 nanofibres with same morphologies and sub-microstructures were fabricated by electrospinning technique in the first time, and explored to modify the detection electrodes of nonenzymatic glucose sensors. The electrochemical results indicated that the NiMoO4 based sensor exhibited a good catalytic activity toward glucose including the low response potential (0.5 V), high sensitivity(193.8 µA mM(-1) cm(-2)) with a linear response region of 0.01-8 mM, low detection limit (4.6 µM) and fast response time (2 s), all of which are superior to the corresponding values of CaMoO4 nanofibres and even higher than those of most reported NiO and Co3O4 catalysts, which is due to the NiMoO4 nanofibres are not only advantageous to electron transfer, but can mediated the electrocatalytic reaction of glucose. This work should provide a new pathway for the design of advanced glucose catalysts for nonenzymatic sensor.
Assuntos
Glucose/química , Molibdênio/química , Nanofibras , Níquel/química , Catálise , Técnicas Eletroquímicas , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução , Óxidos/química , Difração de Raios XRESUMO
Metal-organic frameworks (MOFs) have recently attracted much interest in electrochemical fields due to their controlled porosity, large internal surface area, and countless structural topologies. However, the direct application of single component MOFs is limited since they also exhibit poor electronic conductivity, low mechanical stability, and inferior electrocatalytic ability. To overcome these problems, we implanted multi-walled carbon nanotubes (MWCNTs) into manganese-based metal-organic frameworks (Mn-BDC) using a one-step solvothermal method and found that the introduction of MWCNTs can initiate the splitting of bulky Mn-BDC into thin layers. This splitting is highly significant in that it enhances the electronic conductivity and electrocatalytic ability of Mn-BDC. The constructed Mn-BDC@MWCNT composites were utilized as an electrode modifying material in the fabrication of an electrochemical sensor and then were used successfully for the determination of biomolecules in human body fluid. The sensor displayed successful detection performance with wide linear detection ranges (0.1-1150, 0.01-500, and 0.02-1100 µM for AA, DA and UA, respectively) and low limits of detection (0.01, 0.002, and 0.005 µM for AA, DA and UA, respectively); thus, this preliminary study presents an electrochemical biosensor constructed with a novel electrode modifying material that exhibits superior potential for the practical detection of AA, DA and UA in urine samples.
Assuntos
Ácido Ascórbico/urina , Dopamina/urina , Manganês/química , Nanotubos de Carbono/química , Compostos Organometálicos/química , Ácido Úrico/urina , Urinálise/métodos , Eletroquímica , Eletrodos , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Nanocompostos/química , Temperatura , Fatores de TempoRESUMO
One-dimensional Pd-Au nanowires (Pd-Au NWs) were prepared and applied to fabricate an electrochemiluminescence (ECL) biosensor for the detection of acetylcholinesterase (AChE) activity. Compared with single-component of Pd or Au, the bimetallic nanocomposite of Pd-Au NWs offers a larger surface area for the immobilization of enzyme, and displays superior electrocatalytic activity and efficient electron transport capacity. In the presence of AChE and choline oxidase (ChOx), acetylcholine (ATCl) is hydrolyzed by AChE to generate thiocholine, then thiocholine is catalyzed by ChOx to produce H2O2 in situ, which serves as the coreactant to effectively enhance the ECL intensity in luminol-ECL system. The detection principle is based on the inhibited AChE and reactivated AChE as dual biomarkers, in which AChE was inhibited by organophosphorus (OP) agents, and then reactivated by obidoxime. Such dual biomarkers method can achieve credible evaluation for AChE activity via providing AChE activity before and after reactivation. The liner range for AChE activity detection was from 0.025 U L(-1) to 25 KU L(-1) with a low detection limit down to 0.0083 U L(-1).
Assuntos
Acetilcolinesterase/sangue , Acetilcolinesterase/metabolismo , Ensaios Enzimáticos/métodos , Ouro/química , Nanofios/química , Paládio/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Humanos , Limite de Detecção , Medições Luminescentes/métodos , Nanofios/ultraestruturaRESUMO
Well-cubic perovskite lanthanum aluminate (LaAlO(3)) film on (110) silicon substrate was fabricated by sol-gel method with corresponding inorganic salts. Lanthanum acetate and aluminum acetate glacial acetic acid solutions were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate after being refluxed. (CH(3)CO)(2)O removed nitrates and the crystallized H(2)O completely, acetylacetone (AcAc) was partially bidentated with metallic ion of the metallic acetates and formed La(OAc)(3-x)(AcAc)(x), which were hydrolyzed into La(AcAc)(3-x)(OH)(x) by adding 10 ml 0.4% methyl cellulose (MCL) solution. The La(AcAc)(3-x)(OH)(x), polymerizing and combining with MCL, formed the LaAlO(3) sol precursor with heteropolymeric structure and formed film easily. The epitaxial LaAlO(3) film on Si(110) substrate was crystallized after being annealed in thermal annealing furnace for 650-750 degrees C/30 min. The mor-phologies and microstructures were characterized. The refractive index of the LAO film was 1.942 to 2.007; the dielectric constant and the dissipation factors were estimated to be 23-26 and 2.1x10(-4) - 2.4x10(-4) respectively.