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1.
Adv Mater ; 36(4): e2305818, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37657773

RESUMO

Lithium-sulfur (Li-S) batteries stand out for their high theoretical specific capacity and cost-effectiveness. However, the practical implementation of Li-S batteries is hindered by issues such as the shuttle effect, tardy redox kinetics, and dendrite growth. Herein, an appealingly designed covalent organic framework (COF) with bi-functional active sites of cyanide groups and polysulfide chains (COF-CN-S) is developed as cooperative functional promoters to simultaneously address dendrites and shuttle effect issues. Combining in situ techniques and theoretical calculations, it can be demonstrated that the unique chemical architecture of COF-CN-S is capable of performing the following functions: 1) The COF-CN-S delivers significantly enhanced Li+ transport capability due to abundant ion-hopping sites (cyano-groups); 2) it functions as a selective ion sieve by regulating the dynamic behavior of polysulfide anions and Li+ , thus inhibiting shuttle effect and dendrite growth; 3) by acting as a redox mediator, the COF-CN-S can effectively control the electrochemical behavior of polysulfides and enhance their conversion kinetics. Based on the above advantages, the COF-CN-S endows Li-S batteries with excellent performance. This study highlights the significance of interface modification and offers novel insights into the rational design of organic materials in the Li-S realm.

2.
Adv Mater ; 35(40): e2304511, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37384535

RESUMO

The detrimental growth of lithium dendrites and unstable solid electrolyte interphase (SEI) inhibit the practical application of lithium-metal batteries. Herein, atomically dispersed cobalt coordinate conjugated bipyridine-rich covalent organic framework (sp2 c-COF) is explored as an artificial SEI on the surface of the Li-metal anode to resolve these issues. The single Co atoms confined in the structure of COF enhance the number of active sites and promote electron transfer to the COF. The synergistic effects of the Co─N coordination and strong electron-withdrawing cyano-group can adsorb the electron from the donor (Co) at a maximum and create an electron-rich environment, hence further regulating the Li+ local coordination environment and achieving uniform Li-nucleation behavior. Furthermore, in situ technology and density functional theory calculations reveal the mechanism of the sp2 c-COF-Co inducing Li uniform deposition and promoting Li+ rapid migration. Based on these advantages, the sp2 c-COF-Co modified Li anode exhibits a low Li-nucleation barrier of 8 mV, and excellent cycling stability of 6000 h.

3.
Angew Chem Int Ed Engl ; 62(27): e202303871, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37133306

RESUMO

A novel type of covalent organic frameworks has been developed by assembling definite cobalt-nitrogen-carbon configurations onto carbon nanotubes using linkers that have varying electronic effects. This innovative approach has resulted in an efficient electrocatalyst for oxygen reduction, which is understood by a combination of in situ spectroelectrochemistry and the bond order theorem. The strong interaction between the electron-donating carbon nanotubes and the electron-accepting linker mitigates the trend of charge loss at cobalt sites, while inducing the generation of high spin state. This enhances the adsorption strength and electron transfer between the cobalt center and reactants/intermediates, leading to an improved oxygen reduction capability. This work not only presents an effective strategy for developing efficient non-noble metal electrocatalysts through reticular chemistry, but also provides valuable insights into regulating the electronic configuration and charge behavior of active sites in designing high-performance electrocatalysts.

4.
Angew Chem Int Ed Engl ; 62(20): e202300962, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-36917738

RESUMO

Nickel-rich (Ni≥90 %) layered cathodes are critical materials for achieving higher-energy-density and lower-cost next-generation Li-ion batteries (LIBs). However, their bulk and interface structural instabilities significantly impair their electrochemical performance, thus hindering their widespread adoption in commercial LIBs. Exploiting Ti and Mo diffusion chemistry, we report one-step calcination to synthesize bulk-to-surface modified LiNi0.9 Co0.09 Mo0.01 O2 (NCMo90) featuring a 5 nm Li2 TiO3 coating on the surface, a Mo-rich Li+ /Ni2+ superlattice at the sub-surface, and Ti-doping in the bulk. Such a multi-functional structure effectively maintains its structural integrity upon cycling. As a result, such NCMo90 exhibits a high initial capacity of 221 mAh g-1 at 0.1 C, excellent rate performance (184 mAh g-1 at 5 C), and high capacity retention of 94.0 % after 500 cycles. This work opens a new avenue to developing industry-applicable Ni-rich cathodes for next-generation LIBs.

5.
Research (Wash D C) ; 2022: 9798582, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36299446

RESUMO

In addition to improving ion conductivity and the transference number, single-Li-ion conductors (SLCs) also enable the elimination of interfacial side reactions and concentration difference polarization. Therefore, the SLCs can achieve high performance in solid-state batteries with Li metal as anode and organic molecule as cathode. Covalent organic frameworks (COFs) are leading candidates for constructing SLCs because of the excellent 1D channels and accurate chemical-modification skeleton. Herein, various contents of lithium-sulfonated covalently anchored COFs (denoted as LiO3S-COF1 and LiO3S-COF2) are controllably synthesized as SLCs. Due to the directional ion channels, high Li contents, and single-ion frameworks, LiO3S-COF2 shows exceptional Li-ion conductivity of 5.47 × 10-5 S · cm-1, high transference number of 0.93, and low activation energy of 0.15 eV at room temperature. Such preeminent Li-ion-transported properties of LiO3S-COF2 permit stable Li+ plating/stripping in a symmetric lithium metal battery, effectively impeding the Li dendrite growth in a liquid cell. Moreover, the designed quasi-solid-state cell (organic anthraquinone (AQ) as cathode, Li metal as anode, and LiO3S-COF2 as electrolyte) shows high-capacity retention and rate behavior. Consequently, LiO3S-COF2 implies a potential value restraining the dissolution of small organic molecules and Li dendrite growth.

6.
RSC Adv ; 12(11): 6930-6937, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35424588

RESUMO

Limiting the shuttle effect of polysulfides is an important means to realizing high energy density lithium-sulfur batteries (Li-S). In this study, an efficient electrocatalyst (CNFs@Ni3FeN) is synthesized by anchoring Ni3FeN in the carbon nanofibers (CNFs). The CNFs@Ni3FeN shows electrocatalytic activity and enhances the conversion of polysulfides. After assembling a battery, a high initial capacity (1452 mA h g-1) and favorable long-time cycling stability (100 cycles) with a capacity retention rate of 83% are obtained by the electrocatalysis of Ni3FeN. Compared with unmodified CNFs, the cycling stability of CNFs@Ni3FeN can be greatly improved. The catalytic mechanism is further deduced by X-ray photoelectron spectroscopy (XPS). Our work will inspire the rational design of CNFs@support hybrids for various electrocatalysis applications.

7.
Nanoscale ; 14(3): 823-832, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34985068

RESUMO

NASICON-type Na3Zr2Si2PO12 (NZSP) is supposed to be one of the best potential solid electrolytes with the characteristics of high ionic conductivity and safety for use in solid-state sodium batteries. Many methods have been used to enhance the ionic conductivity of NZSP, among which liquid phase sintering is a simple and rapid method. However, the transport mechanism of sodium ions in a NZSP electrolyte obtained by liquid phase sintering is not clear, and its application in solid-state batteries has not been confirmed. In this study, we synthesized NZSP with Na2SiO3 additives by liquid phase sintering to reduce the sintering temperature and improve the ionic conductivity. NZSP with 5 wt% Na2SiO3 (NZSP-NSO-5) achieves the highest ionic conductivity of 1.28 mS cm-1 and the lowest activation energy of 0.21 eV. Furthermore, the DFT study proves the Na+ diffusion mechanism and the decline in activation energy after addition. Lastly, the Na/Na3V2(PO4)3 battery with a Na2SiO3-added NZSP solid electrolyte exhibits a remarkably extended cycling capacity of 96.6% capacity retention after being cycled at 0.1 C 100 times. The liquid phase sintering with addition of low melting point salt compounds to electrolyte powder represents a rapid and straightforward technique for improving other ceramic electrolytes.

8.
Analyst ; 146(1): 262-269, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33118581

RESUMO

While numerous sensing strategies have been applied in the determination of Acetaminophen (AP), dopamine (DA), and ascorbic acid (AA), the selectivity is always a critical challenge based on their similar structure and function. Accordingly, the development of a highly selective sensing method is not only necessary but also crucial. In this study, a novel electrochemical sensing platform for the simultaneous determination of AP and DA has been successfully constructed based on a multifunctional nanocomposite (WP6-Pd-COF) of water-soluble pillar[6]arene (WP6), ultrafine Pd nanoparticles, and triethylene glycol-modified covalent organic framework (COF). Pd nanoparticles with an average size of 4.2 nm are prepared by reducing K2PdCl4 under the stabilization of oxygen-rich COF, which shows superior catalytic activity in electrochemical detection. A supramolecular host-guest recognition system introduced between WP6 and analytes (AP, DA, and AA) can effectively recognize AP and DA, implying the simultaneous determination of AP and DA by this approach. The electrode, best operated at a working potential range from -0.2 to 0.8 V (vs. Hg/Hg2Cl2), works in the concentration ranges of 0.2-8 µM for DA and 0.1-7.5 µM for AP, and has a detection limit of 0.06 µM for DA and 0.03 µM for AP (S/N = 3). Therefore, this study presents potential application values in sensing, catalysis, and other fields.


Assuntos
Técnicas Biossensoriais , Grafite , Estruturas Metalorgânicas , Nanocompostos , Nanopartículas , Acetaminofen , Ácido Ascórbico , Dopamina , Técnicas Eletroquímicas , Eletrodos , Compostos de Amônio Quaternário , Água
9.
Langmuir ; 36(48): 14676-14685, 2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33227210

RESUMO

In this study, we constructed a highly sensitive and selective electrochemical sensing strategy for l-ascorbic acid (AA) based on a covalent organic framework (COF)-loading non-noble transition metal Co ion and macrocyclic cationic pillar[6]arene (CP6) nanocomposite (CP6-COF-Co). The COF plays a crucial role in anchoring the Co ion according to its crystalline porous and multiple coordination sites and has an outstanding performance for building an electrochemical sensing platform based on a unique two-dimensional structure. Accordingly, the transition-metal Co ion can be successfully anchored on the framework of COF and shows strong catalytic activity for the determination of AA. Moreover, introduction of host-guest recognition based on CP6 and AA can bring new properties for enhancing selectivity, sensitivity, and practical application in real environment. Host-guest interactions between CP6 and AA were evaluated by the 1H NMR spectrum. When compared with other literatures, our method displayed a lower determination limit and broader linear range. To the best of our knowledge, this is the first study carried out for the non-noble transition-metal Co ion, COF, and pillar[6]arene hybrid material in sensing field, which has a potential value in sensing, catalysis, and preparation of advanced multifunction materials.

10.
Nanotechnology ; 31(13): 135705, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-31816606

RESUMO

While tremendous advancements in 2D materials anchoring Au nanoparticles have been made, it is an urgent challenge to explore a green and facile approach for obtaining small-size Au nanoparticles. The rise of 2D covalent organic framework (COF) presents more-promising candidates for constructing excellent sites for loading metal nanoparticles. In this study, a novel 2D heterogeneous hybrid nanomaterial (P6-Au-COF) based on COF and pillar[6]arene (P6) reduced Au nanoparticles (P6-Au) is prepared by a simple and green procedure. The Au nanoparticles with an average small diameter of 2-3 nm are homogeneously dispersed on the surface of the COF. The P6-Au-COF hybrid material shows highly catalytic performance for the reduction of nitrophenol isomers when compared with commercial Pd/C catalyst and other reported materials. The P6-Au-COF hybrid material exhibits durable recyclablility and stability during the catalytic reaction. Considering the outstanding merits of the heterogeneous 2D catalyst of P6-Au-COF as well as the simple and green preparation, this research might not only present enormous opportunities for stabilized, high-performance and sustainable catalysts, but be applied in other frontier study of sustainable functionalized nanocomposites and advanced materials.

11.
Mikrochim Acta ; 186(11): 703, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628541

RESUMO

An ultrasensitive and highly selective electrochemical method is described for the determination of dopamine (DA). It is based on the use of a multi-functional nanomaterial composed of water-soluble pillar[5]arene (WP5), dihydroxylatopillar[5]arene (2HP5)-modified gold nanoparticles (GNPs), and graphitic carbon nitride (g-C3N4), with an architecture of type 2HP5@GNP@WP5@g-C3N4. The modified GNPs were prepared in the presence of 2HP5 that acts as reducing agent and stabilizer in the formation of GNPs. 2HP5@GNP acts as an electrocatalyst in sensing DA. The WP5@g-C3N4 nanocomposite is obtained by π interaction between WP5 and g-C3N4 after sonication in the presence of WP5. The composite serves as a host for recognition and gathering DA on the surface of the electrode. The host-guest recognition mechanism between WP5 and DA is studied by 1H NMR and UV-vis. The electrode, best operated at a working potential of 0.18 V (vs. SCE), works in the concentration range of 0.012-5.0 µM DA and has a 4 nM detection limit. Graphical abstract Schematic illustration of the 2HP5@GNP@WP5@g-C3N4 hybrid nanomaterial for application in voltammetric sensing of dopamine.

12.
Anal Chim Acta ; 1078: 60-69, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358229

RESUMO

A multicomponent functionalized nano-material (Au@CP5@MoS2) is prepared by control assembly of Au nanoparticles on the surface of CP5@MoS2 for sensing and catalysis reduction of toxic explosives p-dinitrobenzene (p-DNB). Firstly, the Au nanoparticles are obtained by a green redox reaction between HAuCl4 and hydroxylatopillar[5]arene (HP5) in the presence of a small amount of hydroxide ion without any harsh reduced agent. The CP5@MoS2 is prepared by a rapidly supramolecule mediated hydrothermal route in the presence of aqueous solution of cationic pillar[5]arene (CP5). Therefore, we construct an electrochemical sensing platform for the high sensitive and selective determination of p-DNB based on the excellent supramolecular recognition of CP5/HP5 and the high catalytic activity of Au nanoparticles. Moreover, the p-DNB can be reduced into 1,4-diaminobenzene by NaBH4 in the presence of the prepared Au@CP5@MoS2, which can reduce the explosion dangerousness of p-DNB to some extent. This strategy might present a prospective value in sensing and reducing toxic explosives.

13.
Spectrochim Acta A Mol Biomol Spectrosc ; 221: 117176, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31158763

RESUMO

We develop a novel and fast colorimetric sensing platform for spermine (Sp) by using macrocyclic host hydroxyl pillar[5]arene (P5) molecule reduced and stabilized Au nanoparticles via the supramolecular host-guest recognition interaction between P5 and Sp. The P5-modified Au nanoparticles (P5-Au) are easily obtained by redox reaction between hydroxyl groups in P5 and Au3+ in HAuCl4, where hydroxyl groups are oxidized to carboxyl groups and Au3+ is reduced to Au0+ under alkali catalysis at room temperature without NaBH4 or other reducing agent. A uniform diameter of about 5.0 nm and wine red color P5-Au nanoparticles can be synthesized by this green and rapid method. The mechanism of redox reaction between P5 and HAuCl4 is studied by the XPS and 13C NMR, and the P5-Au is characterized by the TEM, XRD and XPS.

14.
Mikrochim Acta ; 186(2): 67, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30627869

RESUMO

Nitrogen-doped carbon dots (N-CDs) with a quantum yield of 41 ± 3% and excellent stability were prepared and are shown to be viable probes for the determination of ferric ions, which is a strong quencher of fluorescence. The absorption peak of the N-CDs is located at 325 nm. The optimal excitation and emission wavelengths of the N-CDs are 340 nm and 430 nm, respectively. The fluorometric response to Fe(III) is linear in the ranges between 1.0 and 21.0 µM and between 0.05 and 30.0 µM, and the limits of detection are 0.28 µM in case of colorimetry and 13.5 nM in case of fluorometry. Quenching by Fe(III) is mainly attributed to a combination of chelation (static quenching) and inner filter effect. The N-CDs also can be used as a new sort of fluorescent ink owing to the strong luminous performance and chemical inertness. Graphic abstract The illustration for synthesis of the N-CDs and its applications for colorimetric and fluorescent detection of Fe3+ and fluorescent ink.

15.
RSC Adv ; 9(66): 38372-38380, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-35540210

RESUMO

Graphdiyne (GD), a novel two dimensional (2D) carbon material, has earned a lot of attention in recent years. Constructing a novel hybrid nanomaterial based on GD, macrocyclic host and Au nanoparticles is an effective strategy for heterogeneous catalysis applications. While tremendous advancements in the preparation of two dimensional (2D) materials anchoring Au nanoparticles have been made, it is an urgent requirement to explore a green, efficient and facile approach for obtaining small-sized Au nanoparticles. The use of the 2D material graphdiyne (GD) presents more-promising candidates for constructing excellent sites for loading metal nanoparticles. In this study, a novel 2D heterogeneous hybrid nanomaterial (P5A-Au-GD) based on GD and pillar[5]arene (P5A)-reduced Au nanoparticles (P5A-Au) was successfully prepared. In this strategy, the P5A can reduce HAuCl4 with the aid of NaOH in the dispersion of GD. Accordingly, the generated P5A-Au can immediately interact with GD to form the P5A-Au-GD hybrid nanomaterial without any harsh reduced materials or other energies. The Au nanoparticles with average diameter of 2-3 nm are homogeneously dispersed on the surface of GD. The heterogeneous 2D catalyst of P5A-Au-GD shows high catalytic performances in the reduction of 4-nitrophenol and methylene blue by comparing commercial Pd/C catalyst. Meanwhile, the unique 2D heterogeneous hybrid material P5A-Au-GD exhibits durable recyclability and stability during the catalytic reaction. Considering the outstanding merits of the heterogeneous 2D catalyst of P5A-Au-GD as well as the simple and green preparation, this study might not only present enormous opportunities for the stabilized, high-performance and sustainable catalysts but also be applied in other frontier studies of sustainable functionalized nanocomposites and advanced materials.

16.
Anal Chim Acta ; 1036: 49-57, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30253836

RESUMO

The rational design of electrochemical methods for isomer recognition is a focus of research in the molecular recognition and separation fields. In this work, a novel, rapid, and convenient electrochemical approach for recognition of nitrophenol isomers was constructed based on the alternating layer-by-layer (LbL) assembly of water-soluble cationic and anionic pillar [5]arene on a carboxylic graphene (C-Gra) modified glass carbon electrode. The electrochemical recognition of nitrophenol isomers was investigated by differential pulse voltammetry (DPV). The electrochemical results reveal that both the peak currents of m-nitrophenol (m-NP) and p-nitrophenol (p-NP) increased with the increasing of the layer number of the assembled pillar [5]arene, whereas the peak current of o-nitrophenol (o-NP) decreased with the increased layers, which demonstrated an efficient route for discriminating the nitrophenol isomers. The molecular recognition mechanism was studied by 1H NMR spectra, which indicated that the m-NP and p-NP can be included in the cavity of the pillar [5]arene host. However, the o-NP could not enter into the host of pillar [5]arene, which was ascribed to the formation of intramolecular hydrogen bond of o-NP. The LbL assembly modified GCE was used for detecting p-NP and m-NP. A low detection limit of 0.33 µM (S/N = 3) and a linear response range of 1-90 µM for p-NP were obtained by using this method. And the detection limit of 0.16 µM (S/N = 3) and a linear response range of 0.5-70 µM for m-NP were obtained. This method of LbL assembly modified GCE has potential application in molecular recognition and separation.

17.
Biosens Bioelectron ; 112: 31-39, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29689502

RESUMO

Prostate specific antigen (PSA) is the most significant biomarker for the screening of prostate cancer in human serum. However, most methods for the detection of PSA often require major laboratories, precisely analytical instruments and complicated operations. Currently, the design and development of satisfying electrochemical biosensors based on biomimetic materials (e.g. synthetic receptors) and nanotechnology is highly desired. Thus, we focused on the combination of molecular recognition and versatile nanomaterials in electrochemical devices for advancing their analytical performance and robustness. Herein, by using the present prepared multifunctional hydroxyl pillar[5]arene@gold nanoparticles@graphitic carbon nitride (HP5@AuNPs@g-C3N4) hybrid nanomaterial as robust biomimetic element, a high-performance electrochemical immunosensor for detection of PSA was constructed. The as-prepared immunosensor, with typically competitive advantages of low cost, simple preparation and fast detection, exhibited remarkable robustness, ultra-sensitivity, excellent selectivity and reproducibility. The limit of detection (LOD) and linear range were 0.12 pg mL-1 (S/N = 3) and 0.0005-10.00 ng mL-1, respectively. The satisfying results provide a promising approach for clinical detection of PSA in human serum.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Antígeno Prostático Específico/isolamento & purificação , Neoplasias da Próstata/diagnóstico , Anticorpos Imobilizados/química , Ouro/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Masculino , Nanopartículas Metálicas/química , Antígeno Prostático Específico/química
18.
Biosens Bioelectron ; 91: 863-869, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28160654

RESUMO

A sensitive and selective fluorescence approach based on a competitive host-guest interaction between amphiphilic pillar[5]arene (amPA5) and signal probe (acridine orange, AO)/target molecule (acetaminophen, AP) was developed by using amPA5 functionalized reduced graphene oxide (amPA5-RGO) as a receptor. Due to the host-guest interaction, AO and AP molecules both can enter into the hydrophobic inner cavity of amPA5 that could form a complex of 1:1 guest-host with amPA5 according to the size of molecules and the cavity of amPA5, but the AP interacts more strongly with amPA5 than with AO, so it can detect AP by the host-guest competition. The low detection limit of 0.05µM (S/N=3) and a linear response range of 0.1-4.0µM and 4.0-32µM for AP was obtained by using this method. It had lower detection limit and wider linear range than other methods, therefore, it was successfully utilized to detect AP in serum samples, and exhibited a promising application in practice. The molecular docking studies indicated that the major driving forces for the formation of the inclusion complex of AP and amPA5 are hydrogen bonding, π-π interactions, and hydrophobic interactions.


Assuntos
Acetaminofen/sangue , Analgésicos não Narcóticos/sangue , Grafite/química , Compostos de Amônio Quaternário/química , Espectrometria de Fluorescência/métodos , Tensoativos/química , Calixarenos , Humanos , Limite de Detecção , Simulação de Acoplamento Molecular , Oxirredução , Óxidos/química
19.
Biosens Bioelectron ; 87: 737-744, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27649329

RESUMO

In this work, the molecular recognition of dimethomorph by disulfide bridged ß-cyclodextrin (SS-ß-CD) was studied by UV spectroscopy, 2D NMR, and molecular modeling. The results indicated that the SS-ß-CD/dimethomorph was more stable than ß-CD/dimethomorph, which is ascribed to the fact that the disulfide chain plays an important role in stabilizing the appropriate dual-CD conformation and also promoting the inclusion of the host and guest. In addition, a robust fluorescence method for dimethomorph sensing has been developed based on competitive host-guest interaction by selecting safranine T (ST) as optical indicator and SS-ß-CD functionalized reduced graphene oxide (SS-ß-CD-RGO) as the receptor. Upon the presence of dimethomorph to the pre-formed SS-ß-CD-RGO·ST complex, the ST molecule is displaced by dimethomorph, leading to a "switch-on" fluorescence response. That is due to the fact that the binding constant of the dimethomorph/SS-ß-CD complex was more than 5 times greater than that of ST/SS-ß-CD. The fluorescence intensity of SS-ß-CD-RGO·ST complex increased linearly with increasing concentration of dimethomorph ranging from 0.50 to 20.0µM. The proposed method showed a detection limit of 0.11µM for dimethomorph, and was successfully applied for the determination of dimethomorph residues in vegetables (cabbage, spinach) and environmental samples (water, soil) with good precision and recoveries from 96.5% to 104%.


Assuntos
Dissulfetos/química , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Transferência Ressonante de Energia de Fluorescência/métodos , Morfolinas/análise , beta-Ciclodextrinas/química , Corantes/química , Água Doce/análise , Limite de Detecção , Modelos Moleculares , Fenazinas/química , Solo/química , Verduras/química
20.
Biosens Bioelectron ; 89(Pt 1): 361-369, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27436432

RESUMO

The present work described the comparison of ß-cyclodextrin (ß-CD) and p-sulfonated calix[6]arene (SCX6) functionalized reduced graphene oxide (RGO) for recognition of tadalafil. In this study, tadalafil and two macrocycles (ß-CD and SCX6) were selected as the guest and host molecules, respectively. The inclusion complexes of ß-CD/tadalafil and SCX6/tadalafil were studied by UV spectroscopy and molecular simulation calculations, proving the higher supermolecular recognition capability of SCX6 than ß-CD towards tadalafil. The ß-CD@RGO and SCX6@RGO composites were prepared by a wet-chemical route. The obtained composites were characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, atomic force microscopy, and zeta potential. The SCX6@RGO showed a higher electrochemical response than ß-CD@RGO, which was caused by the higher recognition capability of SCX6 than ß-CD. By combining the merits of SCX6 and the RGO, a sensitive electrochemical sensing platform was developed based on the SCX6@RGO nanohybrids. A linear response range of 0.1-50 µM and 50-1000 µM for tadalafil with a low detection limit of 0.045 µM (S/N=3) was obtained by using this method. The constructed sensing platform was successfully used to determine tadalafil in herbal sexual health products and spiked human serum samples, suggesting its promising analytical applications for the trace level determination of tadalafil.


Assuntos
Calixarenos/química , Técnicas Eletroquímicas/métodos , Grafite/química , Fenóis/química , Tadalafila/sangue , Vasodilatadores/sangue , beta-Ciclodextrinas/química , Técnicas Biossensoriais/métodos , Humanos , Limite de Detecção , Modelos Moleculares , Simulação de Acoplamento Molecular , Oxirredução , Óxidos/química , Plantas Medicinais/química , Sulfonas/química , Tadalafila/análise , Vasodilatadores/análise
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