Showing papers by "Nankai University published in 2011"
TL;DR: Recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed.
Abstract: There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries.
1,384 citations
TL;DR: The synthesis of nanocrystalline M(x)Mn(3-x)O(4) (M = divalent metals) spinels under ambient conditions and their electrocatalytic application is reported.
Abstract: Spinels can serve as alternative low-cost bifunctional electrocatalysts for oxygen reduction/evolution reactions (ORR/OER), which are the key barriers in various electrochemical devices such as metal-air batteries, fuel cells and electrolysers. However, conventional ceramic synthesis of crystalline spinels requires an elevated temperature, complicated procedures and prolonged heating time, and the resulting product exhibits limited electrocatalytic performance. It has been challenging to develop energy-saving, facile and rapid synthetic methodologies for highly active spinels. In this Article, we report the synthesis of nanocrystalline M(x)Mn(3-x)O(4) (M = divalent metals) spinels under ambient conditions and their electrocatalytic application. We show rapid and selective formation of tetragonal or cubic M(x)Mn(3-x)O(4) from the reduction of amorphous MnO(2) in aqueous M(2+) solution. The prepared Co(x)Mn(3-x)O(4) nanoparticles manifest considerable catalytic activity towards the ORR/OER as a result of their high surface areas and abundant defects. The newly discovered phase-dependent electrocatalytic ORR/OER characteristics of Co-Mn-O spinels are also interpreted by experiment and first-principle theoretical studies.
1,145 citations
TL;DR: This review describes the recent developments of highly efficient catalytic asymmetric hydrogenation of enamides, and enamines and specifically focuses on the substrates because hydrogenation is highly dependent on the substrate although the chiral metal catalysts play a significant role.
Abstract: Transition metal-catalyzed enantioselective hydrogenation of enamides and enamines is one of the most important methods for the preparation of optically active amines. This review describes the recent developments of highly efficient catalytic asymmetric hydrogenation of enamides, and enamines. It specifically focuses on the substrates because hydrogenation of enamides and enamines is highly dependent on the substrates although the chiral metal catalysts play a significant role.
858 citations
TL;DR: River flow rate exerted the most significant effect on the first-order attenuation coefficient (K) for sulfonamides, quinolones, and macrolides, with higher flow rates resulting in higher K, probably due to dilution.
Abstract: The occurrence and transport of 12 antibiotics (from the tetracycline, sulfonamide, quinolone, and macrolide families) was studied in a 72-km stretch of the Haihe River, China, and in six of its tributaries. Aqueous and sediment samples were analyzed by HPLC-MS/MS. Sulfonamides were detected at the highest concentrations (24-385 ng/L) and highest frequencies (76-100%). Eight of the 12 antibiotics likely originated from veterinary applications in swine farms and fishponds, and concentrations at these sources (0.12-47 μg/L) were 1-2 orders of magnitude higher than in the effluent of local wastewater treatment plants. Sulfachloropyridazine (SCP) was detected in all swine farm and fishpond samples (maximum concentration 47 μg/L), which suggests its potential usefulness to indicate livestock source pollution in the Haihe River basin. Hydrological and chemical factors that may influence antibiotic distribution in the Haihe River were considered by multiple regression analysis. River flow rate exerted the most significant effect on the first-order attenuation coefficient (K) for sulfonamides, quinolones, and macrolides, with higher flow rates resulting in higher K, probably due to dilution. For tetracyclines, sediment total organic matter and cation exchange capacity exerted a greater impact on K than flow rate, indicating that adsorption to sediments plays an important role in attenuating tetracycline migration. Overall, the predominance of sulfonamides in the Haihe River underscores the need to consider regulating their veterinary use and improving the management and treatment of associated releases.
786 citations
TL;DR: In this article, the recent progress of anode/cathode materials and filling materials as three-dimensional electrodes for microbial fuel cells has been systematically reviewed, resulting in comprehensive insights into the characteristics, options, modifications, and evaluations of the electrode materials and their effects on different actual wastewater treatment.
695 citations
TL;DR: Findings demonstrate that PGRN is a ligand of TNFR, an antagonist of TNFα signaling, and plays a critical role in the pathogenesis of inflammatory arthritis in mice, and suggest new potential therapeutic interventions for various TNF α-mediated pathologies and conditions, including rheumatoid arthritis.
Abstract: The growth factor progranulin (PGRN) has been implicated in embryonic development, tissue repair, tumorigenesis, and inflammation, but its receptors remain unidentified. We report that PGRN bound directly to tumor necrosis factor receptors (TNFRs) and disturbed the TNFα-TNFR interaction. PGRN-deficient mice were susceptible to collagen-induced arthritis, and administration of PGRN reversed inflammatory arthritis. Atsttrin, an engineered protein composed of three PGRN fragments, exhibited selective TNFR binding. PGRN and Atsttrin prevented inflammation in multiple arthritis mouse models and inhibited TNFα-activated intracellular signaling. Collectively, these findings demonstrate that PGRN is a ligand of TNFR, an antagonist of TNFα signaling, and plays a critical role in the pathogenesis of inflammatory arthritis in mice. They also suggest new potential therapeutic interventions for various TNFα-mediated pathologies and conditions, including rheumatoid arthritis.
619 citations
TL;DR: The results show that this multi-functionalized GO has potential applications for targeted delivery and the controlled release of anticancer drugs.
Abstract: A dual-targeting drug delivery and pH-sensitive controlled release system based on multi-functionalized graphene oxide (GO) was established in order to enhance the effect of targeted drug delivery and realize intelligently controlled release. A superparamagnetic GO–Fe3O4 nanohybrid was firstly prepared via a simple and effective chemical precipitation method. Then folic acid, a targeting agent toward some tumor cells, was conjugated onto Fe3O4 nanoparticlesvia the chemical linkage with amino groups of the 3-aminopropyl triethoxysilane (APS) modified superparamagnetic GO–Fe3O4 nanohybrid, to give the multi-functionalized GO. Doxorubicin hydrochloride (Dox) as an anti-tumor drug model was loaded onto the surface of this multi-functionalized GO via π–π stacking. The drug loading capacity of this multi-functionalized GO is as high as 0.387 mg mg−1 and the drug release depends strongly on pH values. Cell uptake studies were carried out using fluorescein isothiocyanate labeled or Dox loaded multi-functionalized GO to evaluate their targeted delivery property and toxicity to tumor cells. The results show that this multi-functionalized GO has potential applications for targeted delivery and the controlled release of anticancer drugs.
500 citations
TL;DR: It is found that intrinsic motivation was more important than extrinsic motivation in inducing participation in crowdsourcing contests, and it is suggested that crowdsourcing contest tasks should preferably be highly autonomous, explicitly specified, and less complex, as well as require a variety of skills.
Abstract: Firms can seek innovative external ideas and solutions to business tasks by sponsoring co-creation activities such as crowdsourcing. To get optimal solutions from crowdsourcing contest participants, firms need to improve task design and motivate contest solvers' participation in the co-creation process. Based on the theory of extrinsic and intrinsic motivation as well as the theory of job design, we developed a research model to explain participation in crowdsourcing contests, as well as the effects of task attributes on intrinsic motivation. Subjective and objective data were collected from 283 contest solvers at two different time points. We found that intrinsic motivation was more important than extrinsic motivation in inducing participation. Contest autonomy, variety, and analyzability were positively associated with intrinsic motivation, whereas contest tacitness was negatively associated with intrinsic motivation. The findings suggest a balanced view of extrinsic and intrinsic motivation in order to encourage participation in crowdsourcing. We also suggest that crowdsourcing contest tasks should preferably be highly autonomous, explicitly specified, and less complex, as well as require a variety of skills.
477 citations
TL;DR: This review summarizes the preparation, electrochemical performances, and structural stability of core-shell nanostructured materials for lithium ion batteries, and discusses the problems and prospects of this kind of materials.
Abstract: Nanomaterials have some disadvantages in application as Li ion battery materials, such as low density, poor electronic conductivity and high risk of surface side reactions. In recent years, materials with core–shell nanostructures, which was initially a common concept in semiconductors, have been introduced to the field of Li ion batteries in order to overcome the disadvantages of nanomaterials, and increase their general performances in Li ion batteries. Many efforts have been made to exploit core–shell Li ion battery materials, including cathode materials, such as lithium transition metal oxides with varied core and shell compositions, and lithium transition metal phosphates with carbon shells; and anode materials, such as metals, alloys, Si and transition metal oxides with carbon shells. More recently, graphene has also been proposed as a shell material. All these core–shell nanostructured materials presented enhanced electrochemical capacity and cyclic stability. In this review, we summarize the preparation, electrochemical performances, and structural stability of core–shell nanostructured materials for lithium ion batteries, and we also discuss the problems and prospects of this kind of materials.
473 citations
TL;DR: The combination of a highly exfoliated, graphene-like MoS₂ cathode and ultrasmall Mg nanoparticle anode is proposed, for the first time, for rechargeable Mg batteries, emphasizing the necessity of rational morphological control of electrode materials.
Abstract: The combination of a highly exfoliated, graphene-like MoS₂ cathode and ultrasmall Mg nanoparticle anode is proposed, for the first time, for rechargeable Mg batteries. Such a configuration exhibits an operating voltage of 1.8 V and a well reversible discharge capacity of ca. 170 mA h g−1, emphasizing the necessity of rational morphological control of electrode materials and opening up new opportunities for rechargeable Mg batteries.
449 citations
TL;DR: In this paper, a series of inkjet printing processes have been studied using graphene-based inks, and the results show that graphene materials can be easily produced on a large scale and possess outstanding electronic properties.
Abstract: A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide (GO) and few-layered graphene oxide (FGO), various high image quality patterns could be printed on diverse flexible substrates, including paper, poly(ethylene terephthalate) (PET) and polyimide (PI), with a simple and low-cost inkjet printing technique. The graphene-based patterns printed on plastic substrates demonstrated a high electrical conductivity after thermal reduction, and more importantly, they retained the same conductivity over severe bending cycles. Accordingly, flexible electric circuits and a hydrogen peroxide chemical sensor were fabricated and showed excellent performances, demonstrating the applications of this simple and practical inkjet printing technique using graphene inks. The results show that graphene materials-which can be easily produced on a large scale and possess outstanding electronic properties-have great potential for the convenient fabrication of flexible and low-cost graphene-based electronic devices, by using a simple inkjet printing technique.
TL;DR: A crucial function for PP2A in dephosphorylating and activating BZR1 is revealed and completes the set of core components of the brassinosteroid-signalling cascade from cell surface receptor kinase to gene regulation in the nucleus.
Abstract: When brassinosteroid levels are low, the GSK3-like kinase BIN2 phosphorylates and inactivates the BZR1 transcription factor to inhibit growth in plants. Brassinosteroid promotes growth by inducing dephosphorylation of BZR1, but the phosphatase that dephosphorylates BZR1 has remained unknown. Here, using tandem affinity purification, we identified protein phosphatase 2A (PP2A) as a BZR1-interacting protein. Genetic analyses demonstrated a positive role for PP2A in brassinosteroid signalling and BZR1 dephosphorylation. Members of the B' regulatory subunits of PP2A directly interact with BZR1's putative PEST domain containing the site of the bzr1-1D mutation. Interaction with and dephosphorylation by PP2A are enhanced by the bzr1-1D mutation, reduced by two intragenic bzr1-1D suppressor mutations, and abolished by deletion of the PEST domain. This study reveals a crucial function for PP2A in dephosphorylating and activating BZR1 and completes the set of core components of the brassinosteroid-signalling cascade from cell surface receptor kinase to gene regulation in the nucleus.
TL;DR: The biomedical applications of poly(N-isopropylacrylamide) microgels in the form of dispersed particles, 2D films and 3D aggregates were reviewed and some recent progress in this area was highlighted.
Abstract: Poly(N-isopropylacrylamide) (PNIPAM) microgel is perhaps the most well-known intelligent soft nanomaterial. Combining the strengths of hydrogel and nanoparticles, with unique stimuli-responsivity, PNIPAM microgels have found numerous biomedical applications, such as drug delivery, biosensing, and so on. Usually they were used as dispersed particles, however, they can also be used as building blocks to fabricate 2D films and 3D aggregates. These nanostructured assemblies exhibit new properties which the dispersed particles do not have, and new biomedical applications have been found for these assemblies. In this paper, the biomedical applications of PNIPAM microgels in the form of dispersed particles, 2D films and 3D aggregates were reviewed and some recent progress in this area was highlighted.
TL;DR: In this article, six kinds of numerical methods commonly used for estimating Weibull parameters are reviewed; i.e., the moment, empirical, graphical, maximum likelihood, modified maximum likelihood and energy pattern factor method.
TL;DR: Among the transition metal nitrides, MoN has superior electrocatalytic activity and a higher photovoltaic performance than WN and Fe2N for dye-sensitized solar cells as mentioned in this paper.
Abstract: Pt-like electrocatalytic activity of MoN, WN, and Fe2N for dye-sensitized solar cells (DSSCs) is demonstrated in this work Among the transition metal nitrides, MoN has superior electrocatalytic activity and a higher photovoltaic performance This work presents a new approach for developing low-cost and highly-efficient counter electrodes for DSSCs
TL;DR: In this paper, 3D hierarchically porous ZnO architectures were synthesized via an amino acid-assisted biomimetic hydrothermal method combined with subsequent calcination, and they were further employed as a support to load Au nanoparticles to construct hybrid nanomaterials for chemical gas sensors.
Abstract: Three-dimensional (3D) hierarchically porous nanostructures with controlled morphology and dimensionality represent one kind of important material and have received enormous attention for a series of applications. In this work, 3D hierarchically porous ZnO architectures were synthesized via an amino acid-assisted biomimetic hydrothermal method combined with subsequent calcination. First a basic zinc carbonate (BZC) precursor with a lamellar spherical morphology assembled by interconnected nanosheets was synthesized. By subsequent calcination, the as-obtained BZC precursor can be facilely transformed into porous ZnO with a large surface area of 193.7 m2/g, while maintaining its 3D hierarchical morphology. The 3D hierarchically porous ZnO superstructures are further employed as a support to load Au nanoparticles (AuNPs) to construct hybrid nanomaterials for chemical gas sensors. The AuNP-functionalized 3D hierarchically porous ZnO nanomaterials, combining the high surface accessibility of porous materials and catalytic activity of small AuNPs, demonstrated excellent sensor properties in terms of higher sensitivity and very fast response. Furthermore, it is expected this AuNP-functionalized 3D hierarchically porous nanostructure may provide a new pathway to develop advanced nanomaterials for applications like gas sensors, low temperature CO oxidation and photocatalysis.
TL;DR: Graphene-based electrothermal elements hold great promise for many practical applications, such as defrosting and antifogging devices as mentioned in this paper, which shows high transmittance and display good heating performance.
Abstract: High-performance and novel graphene-based electrothermal films are fabricated through a simple yet versatile solution process. Their electrothermal performances are studied in terms of applied voltage, heating rate, and input power density. The electrothermal films annealed at high temperature show high transmittance and display good heating performance. For example, the graphene-based film annealed at 800 °C, which shows transmittance of over 80% at 550 nm, can reach a saturated temperature of up to 42 °C when 60 V is applied for 2 min. Graphene-based films annealed at 900 and 1000 °C can exhibit high steady-state temperatures of 150 and 206 °C under an applied voltage of 60 V with a maximum heating rate of over 7 °C s(-1) . For flexible heating films patterned on polyimide, a steady-state temperature of 72 °C could be reached in less than 10 s with a maximum heating rate exceeding 16 °C s(-1) at 60 V. These excellent results, combined with the high chemical stability and mechanical flexibility of graphene, indicate that graphene-based electrothermal elements hold great promise for many practical applications, such as defrosting and antifogging devices.
TL;DR: In this paper, carbon nanotubes are used as spacer in fabricating a 3D hierarchical structure with graphene sheets to prevent restacking of individual graphene sheets by using a simple green hydrothermal route.
Abstract: Aiming at preventing restacking of individual graphene sheets by using a simple green hydrothermal route, we have introduced carbon nanotubes to act as the spacer in fabricating a three-dimensional (3-D) hierarchical structure with graphene sheets. These 3-D hierarchical structure materials have been used to fabricate supercapacitor devices, and a high specific capacitance of 318 F/g for graphene with an energy density of 11.1 (W h)/kg has been achieved.
TL;DR: It is demonstrated that Parkin interacts with and subsequently ubiquitinates dynamin-related protein 1 (Drp1), for promoting its proteasome-dependent degradation and suggesting a potential mechanism linking abnormal Parkin expression to mitochondrial dysfunction in the pathogenesis of Parkinson disease.
TL;DR: In this article, the authors proposed a CO2 capture and utilization (CCU) protocol to solve the energy penalty problem in common CCS without the need for additional heat desorption.
Abstract: Ionic liquids (ILs), a kind of novel green medium composed entirely of cations and anions, have attracted considerable attention due to their unique properties such as non-volatility, tunable polarity, high stability and so on. In this article, the latest progress on the absorption and subsequent conversion of CO2 by using ILs as absorbents, catalysts or promoters will be summarized. The chemical absorption performance of ILs, especially task-specific ionic liquids (TSILs) such as amino-functionalized ILs, superbase-derived protic ILs has been systematically illustrated. Although significant advances have been made, extensive energy input in the desorption process to recover absorbents would still be a crucial barrier to realizing practical carbon capture and sequestration (CCS). On the other hand, efficient applications of CO2 in the synthesis of valuable compounds such as organic carbonates, urea derivatives, oxazolidinones and formic acid can also be promoted by employing TSILs as catalysts/reaction media. We anticipate that an integration of chemical capture of CO2 with its utilization, a so-called CO2 capture and utilization (CCU) protocol would be an ideal strategy to solve the energy penalty problem in common CCS without the need for additional heat desorption. The essence of this CCU concept is to use TSILs for CO2 capture and substantial activation, which could allow catalytic transformation of CO2 to be accomplished smoothly under low pressure (ideally at 1 atm).
TL;DR: The slurry-packed MIL-101(Cr) column for high-performance liquid chromatographic separation of substituted aromatics was reported, allowing fast and selective separation of the ortho-isomer from the other isomers within 3 min using dichloromethane as the mobile phase.
Abstract: The diverse structures and pore topologies, accessible cages and tunnels, and high surface areas make metal–organic frameworks attractive as novel media in separation sciences. Here we report the slurry-packed MIL-101(Cr) column for high-performance liquid chromatographic separation of substituted aromatics. The MIL-101(Cr) packed column (5 cm long × 4.6 mm i.d.) offered high-resolution separation of ethylbenzene (EB) and xylene, dichlorobenzene and chlorotoluene isomers, and EB and styrene. The typical impurities of toluene and o-xylene in EB and styrene mixtures were also efficiently separated on the MIL-101(Cr) packed column. The column efficiencies for EB, m-dichlorobenzene, and m-chlorotoluene are 20000, 13000, and 10000 plates m–1, respectively. The relative standard deviation for five replicate separations of the substituted aromatics was 0.2–0.7%, 0.9–2.9%, 0.5–2.1%, and 0.6–2.7% for the retention time, peak area, peak height, and half peak width, respectively. The MIL-101(Cr) offered high affinit...
TL;DR: Uniform hollow spheres of CoS2 have been successfully synthesized via a facile solvothermal method and electrochemically investigated as anode material for lithium-ion batteries as discussed by the authors.
Abstract: Uniform hollow spheres of CoS2 have been successfully synthesized via a facile solvothermal method and electrochemically investigated as anode material for lithium-ion batteries. The key strategy i...
TL;DR: In this paper, the redox neutral strategy circumvents the use of wasteful metal oxidants and leads to a clean process, and the authors propose a new strategy for a clean manufacturing process.
Abstract: The redox neutral strategy circumvents the use of wasteful metal oxidants and leads to a clean process.
TL;DR: The structure of the nsp16/nsp10 interaction interface shows that nsp10 may stabilize the SAM-binding pocket and extend the substrate RNA-binding groove of nsp15, consistent with the findings in biochemical assays, and suggest that nSp16/Nsp10 interface may represent a better drug target than the viral MTase active site for developing highly specific anti-coronavirus drugs.
Abstract: The 5′-cap structure is a distinct feature of eukaryotic mRNAs, and eukaryotic viruses generally modify the 5′-end of viral RNAs to mimic cellular mRNA structure, which is important for RNA stability, protein translation and viral immune escape. SARS coronavirus (SARS-CoV) encodes two S-adenosyl-L-methionine (SAM)-dependent methyltransferases (MTase) which sequentially methylate the RNA cap at guanosine-N7 and ribose 2′-O positions, catalyzed by nsp14 N7-MTase and nsp16 2′-O-MTase, respectively. A unique feature for SARS-CoV is that nsp16 requires non-structural protein nsp10 as a stimulatory factor to execute its MTase activity. Here we report the biochemical characterization of SARS-CoV 2′-O-MTase and the crystal structure of nsp16/nsp10 complex bound with methyl donor SAM. We found that SARS-CoV nsp16 MTase methylated m7GpppA-RNA but not m7GpppG-RNA, which is in contrast with nsp14 MTase that functions in a sequence-independent manner. We demonstrated that nsp10 is required for nsp16 to bind both m7GpppA-RNA substrate and SAM cofactor. Structural analysis revealed that nsp16 possesses the canonical scaffold of MTase and associates with nsp10 at 1∶1 ratio. The structure of the nsp16/nsp10 interaction interface shows that nsp10 may stabilize the SAM-binding pocket and extend the substrate RNA-binding groove of nsp16, consistent with the findings in biochemical assays. These results suggest that nsp16/nsp10 interface may represent a better drug target than the viral MTase active site for developing highly specific anti-coronavirus drugs.
TL;DR: In this article, the Gamma-Weibull function (GW) and the truncated Normal Weibull (NW) were proposed for the first time to estimate wind energy field, and the results showed that the proposed GW pdf describes best according to the Kolmogorov-Smirnov test, while the NN pdf performs worst.
TL;DR: The novel construction of nanosupramolecular binary vesicles based on host-guest complex formation between p-sulfonatocalix[4]arene and asymmetric viologen, which was identified by UV-vis and fluorescence spectroscopy, dynamic laser scattering, transmission electron microscopy, scanning electron microscope, and surface tension experiments, has been reported.
Abstract: We report the novel construction of nanosupramolecular binary vesicles based on host−guest complex formation between p-sulfonatocalix[4]arene and asymmetric viologen, which was identified by UV−vis and fluorescence spectroscopy, dynamic laser scattering, transmission electron microscopy, scanning electron microscopy, and surface tension experiments. The critical aggregation concentration of asymmetric viologen decreases pronouncedly by a factor of ca. 1000 owing to the complexation of p-sulfonatocalix[4]arene. Furthermore, we have demonstrated that the resulting vesicles can respond to multiple external stimuli, including temperature, host−guest inclusion, and redox. Methods of warming and inclusion of cyclodextrins were then employed to disrupt the vesicle architecture to release hydrophilic doxorubicin from the interior of the vesicle. Finally, cell experiments were performed to evaluate the cellular toxicity of the supramolecular binary vesicle and the anticancer efficiency of doxorubicin-loaded vesicle.
TL;DR: A conjugated small molecule containing a benzodithiophene unit shows high performance in bulk heterojunction (BHJ) solar cells using the simple solution spinning process.
Abstract: A conjugated small molecule containing a benzodithiophene unit shows high performance in bulk heterojunction (BHJ) solar cells. Using the simple solution spinning process, a high PCE is achieved by employing this molecule as the donor in BHJ solar cells.
TL;DR: A GO-based photoinduced charge transfer (PCT) label-free near-infrared (near-IR) fluorescent biosensor for dopamine (DA) and was successfully applied to the determination of DA in biological fluids with quantitative recovery.
Abstract: While the super fluorescence quenching capacity of graphene and graphene oxide (GO) has been extensively employed to develop fluorescent sensors, their own unique fluorescence and its potential for chemo-/biosensing have seldom been explored. Here we report a GO-based photoinduced charge transfer (PCT) label-free near-infrared (near-IR) fluorescent biosensor for dopamine (DA). The multiple noncovalent interactions between GO and DA and the ultrafast decay at the picosecond range of the near-IR fluorescence of GO resulted in effective self-assembly of DA molecules on the surface of GO, and significant fluorescence quenching, allowing development of a PCT-based biosensor with direct readout of the near-IR fluorescence of GO for selective and sensitive detection of DA. The developed method gave a detection limit of 94 nM and a relative standard deviation of 2.0% for 11 replicate detections of 2.0 μM DA and was successfully applied to the determination of DA in biological fluids with quantitative recovery (98...
TL;DR: A newly synthesized photocrosslinkable interpenetrating polymer network (IPN) hydrogel based on gelatin methacrylate and silk fibroin formed by sequential polymerization is described, which possesses tunable structural and biological properties.
TL;DR: The developed tandem ZIF-8 molecular sieves were further used for the determination of linear alkanes in petroleum-based fuel and human serum and to solve headache problems in complex real sample analysis.
Abstract: Metal–organic frameworks (MOFs) were employed to design tandem molecular sieves as a dual platform for selective solid-phase microextraction (SPME) and high-resolution gas chromatographic (GC) separation of target analytes in complex matrixes. An elegant combination of a ZIF-8-coated fiber for SPME with a ZIF-8-coated capillary for GC allows selective extraction and separation of n-alkanes from complex matrixes such as petroleum-based fuel and biological fluids. The proposed tandem ZIF-8 molecular sieves not only offered good enhancement factors from 235 (hexane) to 1212 (nonane), but also exhibited wide linearity with 3 orders of magnitude for the tested linear alkanes. The limits of detection for the linear alkanes ranged from 0.46 ng L–1 (nonane) to 1.06 ng L–1(hexane). The relative standard deviations of retention time, peak area, peak height, and half peak width for five replicate determinations of the tested n-alkanes at 30 ng L–1 were 0.02–0.26%, 1.9–8.6%, 1.4–6.0%, and 1.3–7.2%, respectively. The ...