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1.
Anal Chim Acta ; 1307: 342648, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719409

RESUMO

In contrast to the conventional fluorescence enhancement resulting from the cessation of the photoinduced electron transfer effect upon capturing nitric oxide (NO) by o-phenylenediamine, we found an interesting fluorescence quench within small molecule fluorophores characterized by intramolecular hydrogen bonding. Herein, the integration of a push-pull electron system with intramolecular hydrogen bonding onto an ultra-small fluorophore was employed to fabricate a hydrogen bond-tuned single benzene core fluorescent probe with an exceptional fluorescence quantum yield of 26 %, denoted as HSC-1. By virtue of its small size and low molecular weight (mere 192 g/mol), it demonstrated superior solubility and biocompatibility. Given the optimized conditions, HSC-1 manifested extraordinary linearity in detecting NO concentrations ranging from 0.5 to 60 µM, with an outstanding detection limit of 23.8 nM. Theoretical calculations unraveled the photophysical properties of hydrogen bonding-related probe molecules and highlighted the NO sensing mechanism. This pioneering work offers an important platform for the design of small fluorescence probes only with a single benzene core applied to NO sensing, which will potentially emerge as a new frontier in the area.

2.
Chem Sci ; 15(15): 5548-5554, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38638225

RESUMO

Al-rich (Si/Al = 4-6) Cu-SSZ-13 has been recognized as one of the potential catalysts to replace the commercial Cu-SSZ-13 (Si/Al = 10-12) towards ammonia-assisted selective catalytic reduction (NH3-SCR). However, poor hydrothermal stability is a great obstacle for Al-rich zeolites to meet the catalytic applications containing water vapor. Herein, we demonstrate that the hydrothermal stability of Al-rich Cu-SSZ-13 can be dramatically enhanced via Pr-ion modification. Particularly, after high-temperature hydrothermal aging (HTA), CuPr1.2-SSZ-13-HTA with an optimal Pr content of 1.2 wt% exhibits a T80 (temperature window of NO conversion above 80%) window of 225-550 °C and a T90 window of 250-350 °C. These values are superior to those of Cu-SSZ-13-HTA (225-450 °C for T80 and no T90 window). The results of X-ray diffraction Rietveld refinement, electron paramagnetic resonance (EPR) and spectral characterization reveal that Pr ions mainly located in the eight-membered rings (8MRs) in SSZ-13 zeolite can inhibit the generation of inactive CuOx during hydrothermal aging. This finding is further supported by density functional theory (DFT) calculations, which suggest that the presence of Pr ions restrains the transformation from Cu2+ ions in 6MRs into CuOx, resulting in enhanced hydrothermal stability. It is also noted that an excessive amount of Pr ions in Cu-SSZ-13 would result in the production of CuOx that causes the decline of catalytic performance. The present work provides a promising strategy for creating a hydrothermally stable Cu-SSZ-13 zeolite catalyst by adding secondary metal ions.

3.
Small ; : e2400033, 2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38431941

RESUMO

Reticular heterojunctions on the basis of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have sparked considerable interest in recent research endeavors, which nevertheless have seldom been studied in optoelectronic biosensing. In this work, its utilization for organic photoelectrochemical transistor (OPECT) detection of the important cancer biomarker of neuron-specific enolase (NSE) is reported. A MOF@COF@CdS quantum dots (QDs) heterojunction is rationally designed to serve as the photogating module against the polymeric channel. Linking with a sandwich complexing event, target-dependent alternation of the photogate is achieved, leading to the changed photoelectric conversion efficiency as indicated by the amplified OPECT signals. The proposed assay demonstrates good analytical performance in detecting NSE, featuring a linear detection range from 0.1 pg mL-1 to 100 ng mL-1 , with a detection limit of 0.033 pg mL-1 .

4.
Anal Chem ; 96(5): 2135-2141, 2024 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-38252409

RESUMO

A facile route for exponential magnification of transconductance (gm) in an organic photoelectrochemical transistor (OPECT) is still lacking. Herein, photoresponsive hydrogen-bonded organic frameworks (PR-HOFs) have been shown to be efficient for gm magnification in a typical poly(ethylene dioxythiophene):poly(styrenesulfonate) OPECT. Specifically, 450 nm light stimulation of 1,3,6,8-tetrakis (p-benzoic acid) pyrene (H4TBAPy)-based HOF could efficiently modulate the device characteristics, leading to the considerable gm magnification over 78 times from 0.114 to 8.96 mS at zero Vg. In linkage with a DNA nanomachine-assisted steric hindrance amplification strategy, the system was then interfaced with the microRNA-triggered structural DNA evolution toward the sensitive detection of a model target microRNA down to 0.1 fM. This study first reveals HOFs-enabled efficient gm magnification in organic electronics and its application for sensitive biomolecular detection.


Assuntos
Ácido Benzoico , MicroRNAs , Hidrogênio , Polietileno , DNA
5.
Langmuir ; 39(49): 17830-17843, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38018894

RESUMO

Photocatalytic degradation is a promising method for controlling the increasing contamination of the water environment due to pharmacologically active compounds (PHACs). Herein, oxygen vacancy (OV)-modulated Z-scheme CuWO4/CuBi2O4 hybrid systems were fabricated via thermal treatment by loading of CuWO4 nanoparticles with OVs on CuBi2O4 surfaces. The synthesized CuWO4/CuBi2O4 hybrid samples exhibited an enhanced photodegradation ability to remove PHACs under visible-light irradiation. More importantly, an optimized sample (10 wt % CuWO4/CuBi2O4) exhibited superior catalytic activity and excellent recycling stability for PHAC photodegradation. In addition, possible degradation paths for PHAC removal over the CuWO4/CuBi2O4 hybrid systems were proposed. The enhanced photocatalytic performance could be attributed to the efficient separation and transfer of photoformed charge pairs via the Z-scheme mechanism. This Z-scheme mechanism was systematically analyzed using trapping experiments of active species, ultraviolet photoelectron spectroscopy, electron spin resonance, and the photodepositions of noble metals. The findings of this study can pave the way for developing highly efficient Z-scheme photocatalytic systems for PHAC photodegradation.

6.
Biosens Bioelectron ; 240: 115632, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37647684

RESUMO

In this study, a polyethyleneimine (PEI)/Zr4+-functionalized nanofluidic sensing platform based on nonlinear hybridization chain reaction (NHCR) was developed for PNK activity assay. With the existence of PNK, the hairpin HPNK was cleaved by λ exonuclease, liberating the initiator T-DNA. Then T-DNA triggered the nonlinear HCR in solution and the reaction products were absorbed onto the nanopore, which changed the surface charge of nanofluidic device and could be detected by current-voltage characteristic curves. Compared to traditional linear HCR, the nonlinear HCR exhibits a higher sensitivity and order of growth kinetics, making it a powerful signal amplifier in bioanalysis. Due to the powerful amplification efficiency of nonlinear HCR, high sensitivity of the nanopore and specific recognition site of PNK/λ-Exo, an ultrasensitive and selective PNK sensing approach had been developed and applied to precisely quantitate the PNK activity with a LOD of 0.0001 U/mL. Moreover, utilizing this nanofluidic system as a foundation, we constructed a logic circuit that utilized PNK, adenosine diphosphate (ADP), and (NH4)2SO4 as input elements. ADP and (NH4)2SO4 had a crucial function in facilitating the PNK to regulate the DNA logic gate. By modifying the target and inhibitors, the nanofluidic device could detect a variety of stimuli and execute more advanced logical operations.


Assuntos
Técnicas Biossensoriais , Hibridização de Ácido Nucleico , DNA , Bioensaio , Difosfato de Adenosina
7.
Adv Sci (Weinh) ; 10(20): e2207678, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37171812

RESUMO

With the continuous development of organic semiconductor materials and on-going improvement of device technology, the power conversion efficiencies (PCEs) of organic solar cells (OSCs) have surpassed the threshold of 19%. Now, the low production cost of organic photovoltaic materials and devices have become an imperative demand for its practical application and future commercialization. Herein, the feasibility of simplified synthesis for cost-effective small-molecule acceptors via end-cap isomeric engineering is demonstrated, and two constitutional isomers, BTP-m-4Cl and BTP-o-4Cl, are synthesized and compared in parallel. These two non-fullerene acceptors (NFAs) have very similar optoelectronic properties but nonuniform morphological and crystallographic characteristics. Consequently, the OSCs composed of PM6:BTP-m-4Cl realize PCE of 17.2%, higher than that of the OSCs with PM6:BTP-o-4Cl (≈16%). When ternary OSCs are fabricated with PM6:BTP-m-4Cl:BTP-o-4Cl, the averaged PCE value reaches 17.95%, presenting outstanding photovoltaic performance. Most excitingly, the figure of merit (FOM) values of PM6:BTP-m-4Cl, PM6:BTP-o-4Cl, and PM6:BTP-m-4Cl:BTP-o-4Cl based devices are 0.190, 0.178, and 0.202 respectively. The FOM values of these systems are all among the top ones of the current high-efficiency OSC systems, revealing high cost-effectiveness of the two NFAs. This work provides a general but accessible strategy to minimize the efficiency-cost gap and promises the economic prospects of OSCs.

8.
Anal Chem ; 95(23): 9052-9059, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37249351

RESUMO

The sensitive detection of neuron-specific enolase (NSE) as a biomarker for lung cancer at an early stage is critical but has long been a challenge. The emergence of polarity-switchable photoelectrochemical (PEC) bioanalysis has opened up new avenues for developing highly sensitive NSE sensors. In this study, we present such a biosensor depending on the bioinduced AgI transition on MOF-on-MOF-derived semiconductor heterojunctions. Specifically, treatment of ZnO@In2O3@AgI by bioproduced H2S can in situ generate the ZnO@In2O3@In2S3@Ag2S heterojunction, with the photocurrent switching from the cathodic to anodic one due to the changes in the carrier transfer pathway. Linking an NSE-targeted sandwich immunorecognition with labeled alkaline phosphatase (ALP) catalyzed generation of H2S, such a phenomenon was correlated to NSE concentration with good performance in terms of selectivity and sensitivity and a low detection limit of 0.58 pg/mL. This study offered a new perspective on the use of MOF-on-MOF-derived heterostructures for advanced polarity-switchable PEC bioanalysis.


Assuntos
Técnicas Biossensoriais , Óxido de Zinco , Semicondutores , Fosfopiruvato Hidratase/análise , Eletrodos , Técnicas Eletroquímicas , Limite de Detecção
9.
J Colloid Interface Sci ; 644: 533-545, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37012113

RESUMO

Metal-organic polymers (MOPs) can enhance the photoelectrochemical (PEC) water oxidation performance of BiVO4 photoanodes, but their PEC mechanisms have yet to be comprehended. In this work, we constructed an active and stable composite photoelectrode by overlaying a uniform MOP on the BiVO4 surface using Fe2+ as the metal ions and 2,5-dihydroxyterephthalic acid (DHTA) as ligand. Such modification on the BiVO4 surface yielded a core-shell structure that could effectively enhance the PEC water oxidation activity of the BiVO4 photoanode. Our intensity-modulated photocurrent spectroscopy analysis revealed that the MOP overlayer could concurrently reduce the surface charge recombination rate constant (ksr) and enhance the charge transfer rate constant (ktr), thus accelerating water oxidation activity. These phenomena can be ascribed to the passivation of the surface that inhibits the recombination of the charge carrier and the MOP catalytic layer that improves the hole transfer. Our rate law analysis also demonstrated that the MOP coverage shifted the reaction order of the BiVO4 photoanode from the third-order to the first-order, resulting in a more favorable rate-determining step where only one hole accumulation is required to overcome water oxidation. This work provides new insights into the reaction mechanism of MOP-modified semiconductor photoanodes.

10.
Anal Chim Acta ; 1252: 341057, 2023 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-36935155

RESUMO

The accurate and ultrasensitive detection of multiple methyltransferases was in great request for clinical diagnosis and epigenetic therapy. Here, a novel fluorescence assay was proposed for ultrasensitive CpG methyltransferase (M.SssI) and DNA adenine methyltransferase (Dam) activity detection based on hyperbranched rolling circle amplification (HRCA) and DNA walkers. The biosensor showed an extremely high sensitivity due to the dual-amplification strategy of HRCA and DNA walker. The LOD of the biosensor for M.SssI and Dam methyltransferase was estimated at 0.0004 U/mL and 0.001 U/mL, respectively. Without the presence of M.SssI methyltransferase, the corresponding recognition site of hairpin HM was cleaved by HpaII endonuclease, generating a DNA fragment (T-DNA) and inducing the DNA walker-HRCA reaction. Since the HRCA products contained numerous double-strand DNA (dsDNA), SYBR Green I could be embedded in the dsDNA, leading to a high fluorescent signal. In the presence of M.SssI methyltransferase, the corresponding recognition site of hairpin HM was methylated and the HpaII endonuclease-catalyzed stem of hairpin HM dissociation was hindered, leading to no DNA fragment (T-DNA) present. Hence, the DNA walker-HRCA reaction was not initiated and the fluorescent signal of SYBR Green I remained at a low level. Similarly, DNA adenine methyltransferase (Dam) and its inhibitors could also be detected by redesigning hairpin HD with the Dam recognition sequences. Furthermore, the sensing system was applied to analyze the endogenic Dam methyltransferase in the real samples such as E. coli cell lysate.


Assuntos
Técnicas Biossensoriais , Escherichia coli , Fluorescência , DNA/genética , Metilases de Modificação do DNA , Metiltransferases , Endonucleases
11.
Phys Chem Chem Phys ; 25(12): 8556-8563, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36883834

RESUMO

4-Chloroaniline (4-CAN) plays an important role in chemical and industrial production. However, it remains a challenge to avoid the hydrogenation of the C-Cl bond in the synthesis process to improve selectivity under high activity conditions. In this study, we in situ fabricated ruthenium nanoparticles (Ru NPs) containing vacancies inserted into porous carbon (Ru@C-2) as a highly efficient catalyst for the catalytic hydrogenation of 4-chloronitrobenzene (4-CNB) with remarkable conversion (99.9%), selectivity (99.9%), and stability. Experiments and theoretical calculations indicate that the appropriate Ru vacancies affect the charge distribution of the Ru@C-2 catalyst, promote the electron transfer between the Ru metal and support, and increase the active sites of the Ru metal, thus facilitating the adsorption of 4-CNB and the desorption of 4-CAN to improve the activity and stability of the catalyst. This study can provide some enlightenment for the development of new 4-CNB hydrogenation catalysts.

12.
iScience ; 25(12): 105639, 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36465128

RESUMO

Printable solar cells are promising for low cost and large-scale production. As the two main classes of printable solar cells, organic and perovskite solar cells show distinct advantages and apparent drawbacks. The latter stand as major obstacle toward their commercialization. It is amazing if the advantages of organic and perovskite solar cells are integrated since some of them are complementary. Here, we report ionic-type high-efficiency photovoltaic materials which achieve this goal. We explore 46,388 organic materials from the Crystallography Open Database by extensive quantum mechanical calculations. Through photovoltaic-functionality-directed materials screening, we identify 5 organic ionic-type photovoltaic materials. They show the merits of nontoxic, high dielectric constant (27.03), high theoretical efficiency (28.7%), and superior thermal stability. Our findings propose ionic-type photovoltaic materials, which may surpass traditional organic and perovskite materials and open the door to next-generation printable solar cells.

13.
Dalton Trans ; 51(13): 5184-5194, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35285466

RESUMO

Metal selenides, as potential alternative candidates for sodium storage, have promising applicability due to their high theoretical specific capacity. However, their huge volume change and sluggish electrode kinetics during sodium ion uptake and release processes can result in insufficient cycling life and inferior rate performance, hindering their practical application. Herein, nitrogen (N)-doped carbon-confined cobalt selenide anchored on multiwalled carbon nanotube networks (denoted as CoSe2@NC/MWCNTs) was designed and successfully built through a selenization process with ZIF-67 MOF as the template. The existence of the interconnected MWCNT network plays a crucial role in not only enhancing the electronic conductivity and ion/electron-transfer efficiency but also ensuring structural stability. Consequently, the optimized CoSe2@NC/MWCNTs composite delivers a high reversible capacity of 479.6 mA h g-1 at a current rate of 0.2 A g-1, accompanied by a 92.0% capacity retention over 100 cycles and a predominant rate performance of 227.4 mA h g-1 even under 20 A g-1 when examined as the anode in Na-ion batteries. Moreover, the kinetic behaviors were confirmed using CV profiles at various rates, as well as the galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). Besides, the HRTEM images clearly reveal the sodium-ion storage mechanism of the CoSe2 hybrid. These results make CoSe2@NC/MWCNTs a prospective anode material in advanced sodium-ion batteries.

14.
J Chromatogr A ; 1668: 462923, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35259647

RESUMO

Ligand is an essential part of the cost of adsorbent preparation, which needs to be carefully selected and evaluated. In this paper, we introduced ligand efficiency (Le) with three levels (recovery, preparation and cost) to form a selection strategy for evaluation of the efficiency of hydrophobic charge-induction ligand. These functions were calculated from static/dynamic binding capacity, desorption efficiency, coupling efficiency and ligand cost. Nine kinds of ligand were used to demonstrate this strategy. The coupling efficiency was determined by preparing the adsorbents with different kinds and densities of ligand. These adsorbents were characterized by FT-IR, SEM. Then adsorption equilibrium, adsorption kinetics, and frontal adsorption experiments were used to test the adsorption and desorption performance of these adsorbents. Finally, Les of recovery, preparation and cost were calculated. The results showed there were apparent differences in Les between ligand types and densities under static and dynamic adsorption conditions. 4FF-Tryptophan with 52 µmol/g adsorbent had the best performance with the lowest static/dynamic Le of recovery, preparation and ligand cost. Compared with those methods evaluated by static saturated adsorption capacity or dynamic binding capacity at 10% breakthrough, the selection strategy based on ligand efficiency is more suitable for subsequent research and industrial amplification.


Assuntos
Proteínas , Adsorção , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Proteínas/química , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Chemistry ; 28(22): e202200263, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35233854

RESUMO

Precisely onsite monitoring of hypochlorite (ClO- ) is of great significance to guide its rational use, reducing/avoiding its potential threat toward food safety and human health. Considering ClO- could quench fluorescence of curcumin (CCM) by oxidizing the o-methoxyphenol of CCM into benzoquinone, a portable ratiometric fluorescence sensor integrated with smartphone was designed for realizing the visual point-of-care testing (POCT) of ClO- . The amphiphilic phospholipid polymer was used as carrier to wrap curcumin, forming a novel liposome-encapsulated CCM, which provided a scaffold to bind with [Ru(bpy)3 ]2+ through electrostatic interaction, thus assembling [Ru(bpy)3 ]2+ -functionalized liposome-encapsulated CCM ([Ru(bpy)3 ]2+ @CCM-NPs). Further integrated with smartphone, visual imaging of [Ru(bpy)3 ]2+ @CCM-NPs could be achieved and the accurate onsite detection of ClO- could be realized with a detection limit of 66.31 nM and a linear range of 0.2210 to 80.0 µM. In addition, the sensor could monitor ClO- in real samples with an onsite detection time of ∼154.0 s.


Assuntos
Curcumina , Ácido Hipocloroso , Corantes Fluorescentes , Humanos , Lipossomos , Imagem Óptica , Smartphone
16.
Anal Chem ; 94(10): 4407-4416, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35234450

RESUMO

DNA methylation is catalyzed by a family of DNA methyltransferases that play crucial roles in various biological processes. Therefore, an ultrasensitive methyltransferase assay is highly desirable in biomedical research and clinical diagnosis. However, conventional assays for the detection of DNA methyltransferase activity often involve radioactive labeling, costly equipment, and laborious operation. In this study, an ultrasensitive and label-free method for detecting DNA adenine methyltransferase (Dam) and CpG methyltransferase (M.SssI) was developed using the nanopore technique coupled with DNA cascade signal amplification reactions. A hairpin DNA (HD) comprising of the methylation-responsive sequences was skillfully designed. In the presence of Dam methyltransferase, the corresponding recognition site of hairpin HD was methylated and specifically cleaved by DpnI endonuclease, thus forming a DNA fragment that induces the catalytic hairpin assembly and hybridization chain reaction (CHA-HCR). The generated products could be absorbed onto the Zr4+-coated nanopore, resulting in an ion current rectification signal change. Considering the high sensitivity of the nanopore and excellent specificity toward the recognition of methyltransferase/endonuclease, our developed method could detect both Dam and M.SssI methyltransferases in the same sensing platform. Furthermore, the designed nanopore sensor could realize the multiplex detection of Dam and M.SssI methyltransferases after integration with the cascaded INHIBIT-AND logic gate. This ultrasensitive methyltransferase assay holds great promise in the field of cancer diagnosis.


Assuntos
Técnicas Biossensoriais , Nanoporos , Técnicas Biossensoriais/métodos , DNA , Metilação de DNA , Metilases de Modificação do DNA , Metiltransferases/metabolismo
17.
Top Curr Chem (Cham) ; 380(1): 6, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34878603

RESUMO

Near-infrared (NIR) refers to the section of the spectrum from 650 to 2500 nm. NIR luminescent materials are widely employed in organic light-emitting diodes (OLEDs), fiber optic communication, sensing, biological detection, and medical imaging. This paper reviews organic NIR electroluminescent materials, including organic NIR electrofluorescent materials and organic NIR electrophosphorescent materials that have been investigated in the past 6 years. Small-molecule, polymer NIR fluorescent materials and platinum(II) and iridium(III) complex NIR phosphorescent materials are described, and the limitations of the development of NIR luminescent materials and future prospects are discussed.


Assuntos
Irídio , Luminescência , Polímeros
18.
Anal Chem ; 93(47): 15761-15767, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34779611

RESUMO

The photoanode, photosystem II (PSII)/hierarchical inverse opal (IO) TiO2, is coupled to the complementary photocathode, PbS quantum dots (QDs)/DNA probes, which is then integrated into a two-compartment photoelectrochemical (PEC) cell to achieve a self-powered system to enable photocathodic detection of microRNA-10b from HeLa cells. In such a system, all of the PSII catalytic products, i.e., electrons, protons, and O2, were rationally utilized and could overcome the general issue of varied O2 levels in photocathodic detection. The correlation between the target-triggered formation of the DNA complexes and the catalytic reduction of the dissolved O2 makes possible the steady microRNA-10b detection with good sensitivity and selectivity. This work has unveiled the ability of PSII to construct self-powered detecting devices and shed light on its application in new arenas.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Técnicas Eletroquímicas , Eletrodos , Células HeLa , Humanos , Complexo de Proteína do Fotossistema II
19.
Anal Chim Acta ; 1177: 338787, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482893

RESUMO

The detection of glucose in human blood is of great importance in the diagnosis and prevention of diabetes. In this work, we fabricated a novel electrochemical non-enzymatic glucose sensor, NiCo-LDH nanoflake arrays-supported Au nanoparticles on copper foam (NiCo-LDH@ Au/Cu) by galvanic replacement and electrodeposition methods. Owing to the synergistic effect of three-dimensional (3D) architecture of Cu foam, high electrocatalytic activity of Au nanoparticles and NiCo-LDH nanoflake arrays, the NiCo-LDH@Au/Cu electrode exhibits excellent electrocatalytic ability for glucose oxidation in NaOH solution. Under optimized conditions, the NiCo-LDH@Au/Cu electrode shows excellent activity with a linear range from 0.5 to 3000 µM at the potential of 0.50 V (vs. Ag/AgCl), a low detection limit of 0.23 µM (S/N = 3), an ultra-prompt response time of 0.5 s, and a high sensitivity of 23100 µA mM-1 cm-2, as well as good selectivity and stability. Furthermore, the as-fabricated non-enzymatic glucose sensor was successfully applied to the glucose detection in human serum as a promising candidate in the development of electrochemical non-enzymatic glucose sensor.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Cobre , Técnicas Eletroquímicas , Glucose , Ouro , Humanos
20.
Nanoscale ; 13(20): 9328-9338, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-33988215

RESUMO

Molybdenum disulfide (MoS2) has been regarded as a promising anode material in the field of sodium-ion batteries (SIBs), with the advantages of high theoretical capacity and large interlayer spacings. Unfortunately, its intrinsic poor electrical conductivity and large volume changes during the sodiation/desodiation reactions still limit its practical application. To deal with this shortcoming, we built MoS2 nanosheet/multiwalled carbon nanotube (denoted as MoS2-MSs/MWCNTs) composites with a three-dimensional (3D) micro-spherical structure, assembled in situ from MoS2 nanosheets. These nanosheets are connected to each other by the MWCNTs network, which provides a highly conductive pathway for electrons/ions through interparticle and intraparticle interfaces, accelerating charge transfer and ion diffusion capabilities. More importantly, the carbon network can boost electrical conductivity and relieve structural strain. Consequently, the as-prepared MoS2-MSs/MWCNTs composite presents a high reversible specific capacity of 519 mA h g-1 at 0.1 A g-1 after 100 cycles with a capacity retention of 94.4% and excellent rate performance (227 mA h g-1 at 10 A g-1). Outstanding cycling stability was also achieved (327.1 mA h g-1 over 1000 cycles at 2 A g-1) and was characterized by scanning electron microscopy (SEM) analysis. Our findings provide a simple and effective strategy to explore anode materials with advanced sodium storage properties.

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