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1.
Talanta ; 273: 125836, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38458080

RESUMEN

Herein, a highly novel and effective electrochemiluminescence (ECL) sensor based on metal-organic framework (MOF, HKUST-1) derived CuO nanoneedles (HKUST-1 derived CuO NNs), gold nanoparticles (AuNPs) and TiO2 was developed for ultrasensitive detection of catechol and luteolin. The HKUST-1 derived CuO NNs were employed as luminophore for the first time, which were successfully fabricated by using HKUST-1 as precursor. The results revealed that the HKUST-1 derived CuO NNs exhibit excellent ECL activity ascribed to its abundant active site and the high specific surface area, thus obviously promoting the separation and transfer of charge and further improving the current density of ECL sensor. To binary-amplify the signal of the ECL sensor, the AuNPs and TiO2 nano-materials with good biocompatibility, great electron transport efficiency and high catalytic activity were used as co-reaction accelerators in the ECL process. Dependent on the above brilliant strategy, the proposed ECL sensor achieved wide linear ranges from 3 × 10-9 - 1 × 10-4 M for catechol and 1 × 10-8 - 2 × 10-4 M for luteolin, with the detection limits of 1.5 × 10-9 M for catechol and 5.3 × 10-9 M for luteolin, respectively. Furthermore, the ECL sensor exhibited outstanding selectivity, repeatability, stability and obtained great feedback on determination of catechol and luteolin in actual samples. The method not only filled a gap in the ECL application of MOF-derived materials but also provided a novel sight for design other highly efficient luminescent materials.

2.
Molecules ; 28(8)2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37110631

RESUMEN

In this study, the preparation of covalent polyoxometalate organic frameworks (CPOFs) is introduced using the idea of polyoxometalate and covalent organic frameworks. Firstly, the prepared polyoxometalate was functionalized with an amine group (NH2-POM-NH2), and then the CPOFs were prepared by a solvothermal Schiff base reaction with NH2-POM-NH2 and 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde (Tp) as monomers. After the incorporation of PtNPs and MWCNTs into the CPOFs material, the PtNPs-CPOFs-MWCNTs nanocomposites, which possess excellent catalytic activity and electrical conductivity, were formed and utilized as new electrode materials for the electrochemical thymol sensors. The obtained PtNPs-CPOFs-MWCNTs composite exhibits excellent activity toward thymol, which is attributable to its large special surface area, good conductivity and the synergistic catalysis of each component. Under optimal experimental conditions, the sensor presented a good electrochemical response to thymol. The sensor shows two good linear relationships between the current and thymol concentration in the range of 2-65 µM (R2 = 0.996) and 65-810 µM (R2 = 0.997), with the corresponding sensitivity of 72.7 µA mM-1 and 30.5 µA mM-1, respectively. Additionally, the limit of detection (LOD) was calculated to be 0.2 µM (S/N = 3). At the same time, the prepared thymol electrochemical sensor revealed superior stability and selectivity. The constructed PtNPs-CPOFs-MWCNT electrochemical sensor is the first example of thymol detection.

3.
Anal Methods ; 15(9): 1168-1177, 2023 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-36790872

RESUMEN

Methyl parathion (MP) is a widely used organophosphate insecticide that is extremely toxic due to its ability to irreversibly inhibit acetylcholinesterase in the body and persistently accumulate in the environment. Timely detection of MP can prevent harmful residue exposure to humans. Therefore, the development of fast, efficient electrochemical methods to detect trace MP has been highly beneficial for monitoring harmful residues in foods and environment to ensure food safety and ecological conservation. Herein, a novel hybrid metal-organic framework (MOF) nanocomposite composed of Pt nanoparticles (PtNPs), multi-walled carbon nanotubes (MWCNTs), and UiO-66-NH2 (PtNPs/UiO-66-NH2/MWCNTs) was rationally designed and prepared by a facile two-step strategy for the sensitive determination of MP. The synergistic effects are illustrated in detail using XRD, XPS, FTIR, TEM, and SEM studies as well as electrochemical technologies such as CV, EIS, and DPV. In addition, the performance of the ternary nanocomposite for detecting MP was investigated by comparing it with the binary-component one. The results showed that the PtNPs/UiO-66-NH2/MWCNT-based electrochemical sensor exhibited outstanding sensitivity of 21.9 µA µM-1 cm-2, satisfactory low detection limit of 0.026 µM and wide linear range of 0.11-227.95 µM for MP analysis. Furthermore, the fabricated sensor delivered distinguished freedom from interferences, outstanding regeneration ability, and adequate recoveries for fresh foods and river water samples. In conclusion, the proposed PtNPs/UiO-66-NH2/MWCNT-based sensor provides a potentially useful analytical tool for determining hazardous residues of OPs in foods and the environment.


Asunto(s)
Estructuras Metalorgánicas , Metil Paratión , Nanocompuestos , Nanotubos de Carbono , Humanos , Organofosfatos , Nanotubos de Carbono/química , Acetilcolinesterasa/química , Metil Paratión/análisis , Nanocompuestos/química
4.
Macromol Rapid Commun ; 44(6): e2200846, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36573846

RESUMEN

Stimuli-responsive nanoporous materials represent a newly emerging category of functional materials, for which instant and significant response behavior is strongly demanded but still challenging. Herein, a new kind of conjugated poly(ionic liquid)s (PILs) synthesized via a simple one-pot spontaneous nucleophilic substitution and polymerization between 4,4'-vinylenedipyridine and propargyl bromide is reported. A nanoporous membrane actuator is further developed via ionic complexation between the current PIL and trimesic acid. The actuator carries a gradient density in the hydrophobicity content along the membrane cross-section, which results in a fast response to moisture.


Asunto(s)
Líquidos Iónicos , Nanoporos , Polímeros de Estímulo Receptivo , Polimerizacion
5.
ACS Appl Mater Interfaces ; 14(51): 57387-57398, 2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36512607

RESUMEN

Stretchable, healable, biocompatible, and conductive hydrogels are one of the promising candidates for both wearable electronics and environmental remediation applications. To date, the design of hydrogels that integrate ultrafast self-healing with high efficiency (seconds), high stretchability, and biocompatibility and reversibility into one system is not an easy task. Herein, we demonstrate a general oxidation approach to accelerate the hydrogelation of hPEI-based double network gels via the generation of fluorescent polymer clusters at room temperature or triggered by the heating-cooling process. The resulting ohPEI hydrogel has the merit of biocompatibility over most reported hPEI hydrogels for strain sensors. It shows a high conductivity (1.3 S/m), an ultrafast self-healing ability (<3 s, 98% healing efficiency within 60 s), a high stretchability (∼1850 and ∼7000% in deformation), and reversible adhesivity on various material surfaces. The excellent performance of the hydrogel is ascribed to the cooperative and hierarchical interactions of four types of dynamic combinations, including the reversible borate bond, hydrogen bonding, electrostatic interaction, and polymer cluster interactions. The reversible fabrication process by the one-spot method (just by simple mixing of the components) and superior properties of the hydrogel make it an ideal candidate for a wearable strain sensor to monitor human motions and physiological activities. Moreover, it is also a good hydrogel absorbent for phase separation absorption of volatile organic compounds with a high capacity (for acetone: 4.75 g g-1), reusability, and an easy handling process.

6.
Anal Chem ; 94(32): 11201-11208, 2022 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35920591

RESUMEN

Amyloid-ß oligomer (AßO) is widely regarded as a reliable biomarker for the early diagnosis of Alzheimer's disease (AD). In this study, a signal on-off ratiometric electrochemical immunosensor has been developed for ultrasensitive detection of AßO. To achieve the dual-signal ratiometric strategy, ultrasmall copper sulfide nanoparticle-engineered covalent organic framework hybrid nanocomposites (CuS@COFs) were utilized as excellent electrocatalysts toward hydroquinone (HQ) oxidation to produce detectable signals. Meanwhile, electroactive thionine (Thi) and Aß antibody-modified gold nanoparticles (Thi-AuNPs-Ab bioconjugates) were designed as another electrochemical indicator. Based on these two signals, an ultrasensitive sandwich-like electrochemical immunosensor was established for AßO detection. The introduction of AßO resulted in a remarkable decline in the electrochemical signal of HQ but an increase in the signal of Thi. Under optimum conditions, the ratios between the double signals (IThi/IHQ) showed a proportional linear relationship with the AßO concentration (1 pM-1 µM) with a low detection limit of 0.4 pM (S/N = 3), and the biosensor was able to determine the content of AßO in real cerebrospinal fluid samples with satisfactory results. The ratiometric strategy proposed in our study offers a sensitive and efficient approach for early diagnosis of AD, and this work will promote the further applications of engineered COFs in electrochemical sensors.


Asunto(s)
Enfermedad de Alzheimer , Técnicas Biosensibles , Nanopartículas del Metal , Estructuras Metalorgánicas , Enfermedad de Alzheimer/diagnóstico , Péptidos beta-Amiloides/líquido cefalorraquídeo , Técnicas Biosensibles/métodos , Cobre , Técnicas Electroquímicas/métodos , Oro/química , Humanos , Inmunoensayo/métodos , Límite de Detección , Nanopartículas del Metal/química , Estructuras Metalorgánicas/química , Sulfuros
7.
Mikrochim Acta ; 189(9): 323, 2022 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-35933502

RESUMEN

A new strategy is proposed for ultrasensitive detection of chlorogenic acid (CGA) by fabricating an electrochemiluminescence resonance energy transfer (ECL-RET) sensing platform. The novel system designed by introducing ruthenium-based 2D metal-organic framework nanosheets (Ru@Zn-MOF) as ECL acceptor and L-cysteine capped CdS quantum dots (L-CdS QDs) as ECL donor, exhibited good ECL response. The possible mechanism of the modified electrode surface reaction was discussed. Modifying of the electrode surface by application of L-CdS QDs directly on ultrathin MOF nanosheets greatly shortened the electron-transfer distance and reduce energy loss, therefore significantly improving the ECL efficiency. The prepared sensor demonstrated good stability and highly selective detection of the target molecule. Under optimal conditions, the constructed sensor for the detection of CGA exhibited a wide linear range from 1.0 × 10-10 to 1.0 × 10-4 mol·L-1 and a low detection limit of 3.2 × 10-11 mol·L-1 with a correction coefficient of 0.995. The recovery for spiked samples was calculated to be 94.4-109% and the RSD was 1.07-1.72% in real samples. The obtained sensor is considered to be a promising platform for CGA detection. Electrochemiluminescence resonance energy transfer (ECL-RET) sensing platform is used for the detection for chlorogenic acid.


Asunto(s)
Técnicas Biosensibles , Puntos Cuánticos , Rutenio , Ácido Clorogénico , Técnicas Electroquímicas , Transferencia de Energía , Mediciones Luminiscentes
8.
J Pharm Biomed Anal ; 219: 114956, 2022 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-35882178

RESUMEN

In this work, ß-cyclodextrin porous polymers (P-CDPs) functionalized novel covalent organic frameworks (P-CDPs/COFs) were synthesized by a simple and facile method. After combined with Pd2+ via electrostatic interaction, the Pd2+@P-CDPs/COFs nanocomposites were prepared and utilized as novel electrode materials to fabricate the non-enzyme electrochemical sensors for high-sensitivity detection of Norfloxacin (NF). Due to the host-guest recognition, excellent adsorption performance and catalytic performance of Pd2+@P-CDPs/COFs, the prepared sensor exhibited excellent electrochemical performance for detecting NF under the optimum conditions, which showed two linear ranges of 0.08-7.0 µM and 7.0-100.0 µM with a low detection limit of 0.031 µM (S/N = 3). Additionally, the obtained sensor has also been successfully applied to measure NF with satisfactory results in the real medicinal samples of NF eye-drops. Our findings paved the way for the development of COFs-based sensing platform in drug analysis and testing for human health, food security and the quality control of drugs.


Asunto(s)
Estructuras Metalorgánicas , Nanocompuestos , Humanos , Adsorción , Norfloxacino
9.
J Pharm Biomed Anal ; 212: 114653, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35152006

RESUMEN

In this work, the superoxide dismutase (SOD) biomimetic enzyme based on nickel phosphate nanorods [Ni(PO4)NRs] was prepared by a simple and eco-friendly hydrothermal method. After further introduction of carboxylated multi-walled carbon nanotubes (C-MWCNTs), the obtained Ni(PO4)NRs/C-MWCNTs nanocomposites were utilized as the novel electrode materials to construct the electrochemical superoxide anion radicals (O2•-) biosensor with excellent electrical conductivity and unprecedented catalytic performance. The morphology of Ni(PO4)NRs/C-MWCNTs nanocomposite was examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman microscope, respectively. Under the optimum conditions, the proposed biosensor exhibits high sensitivity (5.67 × 104 µA/mM/cm2), low detection limit (0.097 µM at S/N = 3) and good selectivity to O2•-. In addition, the sensor can monitor O2•- released from MCF-7 cells with satisfactory results, which provides a great opportunity to apply it in the field of fundamental research and clinical diagnostics. Our results would promote Ni(PO4)NRs as the SOD biomimetic enzyme for designing biosensor and expand its various applications in biocatalysis and bioanalysis.


Asunto(s)
Técnicas Biosensibles , Nanocompuestos , Nanotubos de Carbono , Biomimética , Técnicas Biosensibles/métodos , Técnicas Electroquímicas , Electrodos , Nanocompuestos/química , Nanotubos de Carbono/química , Níquel/química , Fosfatos/química , Superóxidos/análisis
10.
ACS Appl Mater Interfaces ; 13(33): 40079-40087, 2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34379399

RESUMEN

Coordination-driven self-assembly with controllable properties has attracted increasing interest because of its potential in biological events and material science. Herein, we report on the remote, instant, and switchable control of competitive coordination interactions via ultrasound and heat stimuli in a hydrogel network. Configurational coordination changes result in the transformation of blue-emissive and opaque Al3+-amide aggregations to yellow-green-emissive and transparent Al3+-terpyridine aggregations. Interestingly, circularly polarized luminescence "off-on" switches of the metallo-supramolecular assembly are also created by these configuration changes. Additionally, the impact of the stoichiometric ratio of Al3+ and LysTPY on the assembly is also studied in detail. With a higher content of Al3+, the hydrogel with branched and abundant junctions exhibited robust, self-healing, and self-supporting properties. This in-depth understanding of the coordination interaction adjustment will afford new insights into the preparation of stimuli-responsive metallogels.

11.
RSC Adv ; 11(4): 2446-2452, 2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-35424163

RESUMEN

This study reports a new type of artificial nanozyme based on Hemin-doped-HKUST-1 (HKUST-1, also referred to as MOF-199; a face-centered-cubic MOF containing nanochannels) as a redox mediator for the detection of dopamine (DA). Hemin-doped-HKUST-1 was successfully synthesized by one-pot hydrothermal method, which was combined with reduced graphene oxide (rGO) modified on a glassy carbon electrode (GCE) to construct a sensor (Hemin-doped HKUST-1/rGO/GCE). The morphology and structure of Hemin-doped-HKUST-1 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and infrared spectra (IR) techniques. The Hemin-doped HKUST-1/rGO nanozyme showed an excellent electrocatalytic activity for DA oxidation, which is due to the enhanced Hemin activity through the formation of a metal-organic framework (MOFs) and the synergy between the Hemin-doped HKUST-1 and rGO in nanozyme. The resulted sensor exhibited a high sensitivity of 1.224 µA µM-1, with a lower detection limit of 3.27 × 10-8 M (S/N = 3) and a wide linear range of 0.03-10 µM for DA detection. In addition, due to the stabilizing effect of MOFs on heme, the sensor showed satisfactory stability and has been successfully applied to the detection of DA in serum samples, indicating that this work has potential value in clinical work.

12.
Inorg Chem ; 59(6): 3974-3982, 2020 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-32108475

RESUMEN

Self-healing and tough gels with intriguing white-light emission, prepared by lanthanide metal ions, are highly desirable and remain a challenging topic. In this study, we present the preparation of a hybrid gel that contains poly(methyl methacrylate)/polyacrylic acid (PMMA/PAA) as the organic network and titania as the inorganic network, which are interpenetrating and linked by lanthanide metal ions. Interestingly, the gelation process for the organic phase allows for the efficient phase separation of the water-THF mixture (separation efficiency: >88%), either by the heating-cooling process or by the room temperature gelation that originated from xerogels. The as-prepared gels are self-healing and robust, based on the hybrid networks and dynamic coordination interactions. Specifically, the hybrid gels exhibit various colors of luminescence, depending on either the stoichiometric ratio of Eu3+ and Tb3+ or the excitation wavelengths. Upon excitation by the 365 nm light, the hybrid gel with Eu3+/Tb3+ ions (molar ratio 1:30) demonstrates a white-light emission color. The results also show that the gels prepared by only Eu3+ and Tb3+ possess different morphologies, surface areas, and contact angles. This work presents, for the first time, the crucial role of lanthanide ions for preparing a robust, self-healing hybrid gel with interpenetrating networks in the polymerization process, and the resulting hydrophobic surfaces are related to the phase-selective ability of the gels.

13.
Chem Commun (Camb) ; 56(16): 2439-2442, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-31996873

RESUMEN

A Zr-cluster based metallogel is synthesized via an unusual one-pot solvothermal method. The resulting metallogel is robust, adaptive, self-healing, highly thermostable and conductive. Moreover, the metallogel exhibits reversible stimuli-responsive properties. The gel could respond to at least four kinds of stimuli such as light, aliphatic amines, electricity and metals with color and fluorescence tunability. Importantly, the metallogel with electrochromic properties could be used as soft electrochromic devices for smart windows and electro display boards, and metalchromism provides a practical way for coating corrosion monitoring of metal materials.


Asunto(s)
Complejos de Coordinación/química , Temperatura , Circonio/química , Aminas/química , Complejos de Coordinación/síntesis química , Geles/síntesis química , Geles/química , Estructura Molecular , Tamaño de la Partícula , Propiedades de Superficie
14.
Mater Sci Eng C Mater Biol Appl ; 108: 110214, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31923933

RESUMEN

In this work, PdNPs@ZnO-Co3O4 was synthesized via the facile oxidation treatment of bimetallic ZnCo-zeolitic-imidazolate-framework (ZnCo-ZIF) followed by in situ chemical reduction of PdNPs on the surface of the nanocrystals. After combined with MWCNTs, the PdNPs@ZnO-Co3O4-MWCNTs nanocomposites were formed, which were then exploited as novel electrode materials to construct the non-enzyme electrochemical sensors for high-sensitivity detection of tanshinol. Due to the high catalytic activity of multi-metallic PdNPs@ZnO-Co3O4, and the excellent charge transfer property between imidazole groups of the ligands in MOFs and MWCNTs, the obtained sensor exhibited high sensitivity for tanshinol detection under optimum experimental conditions. The sensor shows two well linear relationship between the current and tanshinol concentration in the range of 0.002-0.69 mM (R2 = 0.989) and 0.69-3.75 mM (R2 = 0.994) with the corresponding sensitivity of 59.16 µA mM-1 and 19.08 µA mM-1. And the limit of detection (LOD) was calculated to be 0.019 µM (S/N = 3). Furthermore, with the advantages of good repeatability, stability and selectivity, the fabricated sensor can be successfully applied to measurement of tanshinol in real medicinal liquids samples. Our results would accelerate the applications of MOFs in electrochemical field and provide insights into design of multifunctional non-enzyme sensing materials for various applications in biocatalysis, bioanalysis and drug testing.


Asunto(s)
Ácidos Cafeicos/análisis , Cobalto/química , Técnicas Electroquímicas , Nanocompuestos/química , Nanotubos de Carbono/química , Óxidos/química , Paladio/química , Óxido de Zinc/química , Oxidación-Reducción
15.
Ultrason Sonochem ; 58: 104659, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31450314

RESUMEN

Herein, instant and precise control of fluorescent emission color and transmittance could be carried out by ultrasound-promoted gel-to-gel transition of naphthalimide derivatives containing CN unit. It is proved that ultrasound triggered an irreversible and efficient configuration transformation of N1 from "trans to cis" form in gel state, which is stabilized by intermolecular hydrogen bonding interaction and not observed in the solution state.

16.
ACS Appl Mater Interfaces ; 11(21): 19605-19612, 2019 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-31062584

RESUMEN

Herein, we report the versatile ways to prepare both low-molecular weight hydrogels and polymeric hydrogels based on various types of supramolecular interactions, starting from a simple amphiphilic terpyridine-based molecule TPYA. Notably, we report that stable terpyridine-based radicals can be generated by light or heat irradiation in polymeric hydrogels based on hydrogen bonding interactions between -COOH of PAA and the terpyridine motif of TPYA for the first time. The generation of radicals is confirmed by EPR and UV-vis experiments, and the process is accompanied by significant color changes from white to dark purple. The stable radical hydrogels prepared by the supramolecular strategy are self-healing, stretchable, and self-supporting and can be molded into different geometrical shapes. It is deduced that the generation of terpyridine-based radicals enhances the intermolecular hydrogen bonding and π-π interaction of molecules in a hydrogel matrix, which is responsible for the self-healing ability. Finally, we also show that the radical gels can selectively respond to ammonia and stretch with reversible color changes based on the reversible hydrogen-bonding interaction.

17.
Biosens Bioelectron ; 138: 111313, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31108380

RESUMEN

A ratiometric electrochemical biosensor was constructed to detect telomerase activity based on electrocatalysis of cerium-based metal-organic frameworks (CeMOFs) and conformation switch of hairpin DNA. First, the CeMOFs were synthesized using Ce as nodes and 1,3,5-benzenetricarboxylic acid as linker in a green method, and then functionalized with gold nanoparticles. The resulted Au@CeMOF tags demonstrated an excellent electrocatalysis toward hydroquinone oxidation. Meanwhile, a methylene blue (MB) modified hairpin probe was designed with telomerase primer (TP) hybridized "stem" and immobilized on the electrode surface via Au-S chemistry. In the presence of the dNTPs and telomerase, the extended TP can open the hairpin DNA and keep the MB away from the electrode surface, resulting in a decrease of electrochemical signal. In the meantime, the TP-extended part could capture the Au@CeMOF-cDNA tags on the electrode surface via hybridization, leading to the increase electrochemical signal of hydroquinone oxidation catalyzed by Au@CeMOF-cDNA tags. Thus, a ratiometric signal output mode was developed for the electrochemical detection of telomerase activity. This biosensor showed wide dynamic correlation of telomerase activity from 2 × 102 to 2 × 106 cells mL-1 with the limit of detection of 27 cells mL-1, and was applied to evaluate telomerase activity in single cell. The ratiometric electrochemical strategy based on the catalysis of MOFs provides a new avenue on signal transduction in telomerase detection.


Asunto(s)
Cerio/química , Oro/química , Nanopartículas del Metal/química , Estructuras Metalorgánicas/química , Telomerasa/análisis , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Catálisis , ADN/química , Técnicas Electroquímicas , Electrodos , Células HeLa , Humanos , Hidroquinonas/química , Límite de Detección , Azul de Metileno/química , Conformación de Ácido Nucleico , Oxidación-Reducción , Telomerasa/metabolismo
18.
Nanoscale ; 11(9): 4044-4052, 2019 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-30768104

RESUMEN

Biomolecule-based hydrogels have potential use in a wide range of applications such as controlled drug release, tissue engineering, and biofabrication. Herein, driven by specific interactions between ds-DNA (double-stranded DNA) and Zn2+ based metal-complexes, we report that the use of DNA as cross-linkers can enhance interactions between self-assembling Zn2+ complexes containing terpyridine and sugar groups in the generation of bioinspired hydrogels from solutions or suspensions. The gelation process is fast and straightforward without tedious steps and happens at room temperature. Such a hydrogelation process of different Zn2+ complexes endows the visualized and selective DNA analogue discrimination. Several experiments suggest that the strong intercalation binding of Zn2+ complexes with ds-DNA results in the unzipping of ds-DNA into ss-DNA (single-stranded DNA), which further behave as linkers to enhance the intermolecular interactions of self-assembling Zn2+ complex molecules via coordination interactions. This work demonstrates an efficient and universal strategy to prepare hydrogels based on biomolecular recognition. Moreover, the DNA responsive behaviors of Zn2+ complexes are further compared with that of solutions and cells.


Asunto(s)
Complejos de Coordinación/química , ADN/química , Hidrogeles/química , Piridinas/química , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/toxicidad , ADN de Cadena Simple/química , Células HeLa , Humanos , Células MCF-7 , Microscopía Confocal , Zinc/química
19.
Analyst ; 143(13): 3075-3084, 2018 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-29862399

RESUMEN

A novel non-enzymatic electrochemical sensor for highly sensitive and selective detection of dopamine was developed based on a 3,4,9,10-perylene tetracarboxylic acid functionalized graphene-multiwalled carbon nanotube-gold nanoparticle nanocomposite modified glassy carbon electrode (PTCA-RGO-MWCNTs-Au NPs/GCE). The nanocomposite film was prepared by a facile, eco-friendly and controllable route and its morphology was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopic (EDX) analysis, and X-ray diffraction (XRD) spectroscopy, respectively. Cyclic voltammetry and chronoamperometry were used for evaluating the electrochemical behaviors of the prepared sensor. The DA sensor exhibited excellent electrochemical performance toward DA with a sensitivity as high as 0.124 µA mM-1, a wide linear range of 1-100 µM and a low detection limit of 0.07 µM (S/N = 3). Moreover, it showed good selectivity toward DA without any obvious interference by AA and UA. Furthermore, the prepared DA sensor was applied to detect DA in real samples with satisfactory results.


Asunto(s)
Dopamina/análisis , Oro , Nanopartículas del Metal , Nanotubos de Carbono , Perileno/análogos & derivados , Técnicas Electroquímicas , Electrodos , Grafito , Nanocompuestos , Perileno/química
20.
Bioelectrochemistry ; 118: 75-82, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28746901

RESUMEN

A simple, ultrasensitive peroxynitrite anion (ONOO-) electrochemical sensing platform was developed by immobilizing hemin on a density controllable electrochemically reduced graphene oxide-Au nanoparticles (ERGO-AuNPs) nanohybrids. The ERGO-AuNPs in situ nanohybrids were produced onto a glass carbon electrode (GCE) by one-step electrodeposition, the density of which could be easily controlled by electrodeposited time. The morphology of ERGO-AuNPs nanohybrids was characterized by a scanning electron microscope (SEM). The ERGO-AuNPs nanohybrids showed a high electrocatalytic activity for immobilized-hemin, because the nanostructures hybrids could effectively promote electron transfer rate between hemin and the electrode. Due to nanohybrids-enhanced catalytic effect for hemin, they were firstly selected for use as a highly sensitive electrochemical platform for ONOO- detection. The resulted sensor showed a high electrocatalytic activity toward ONOO- oxidation, being free from the electroactive interferents, including nitrite, nitrate, dopamine and uric acid at an applied potential of 0.7V. The sensor exhibited a high sensitivity of 123.1nAµM-1 and a lower detection limit of 0.1µM, and a wide linear range of 2.4×10-6 to 5.5×10-5M, which could be attributed to the synergy between ERGO and AuNPs in hybrids. The nanohybrids in situ preparation and ONOO- detection methods would be beneficial to developing other sensing interface and have promising applications in biological molecules analysis and clinical diagnostic.


Asunto(s)
Técnicas Biosensibles/métodos , Oro/química , Grafito/química , Hemina/química , Nanopartículas del Metal/química , Ácido Peroxinitroso/análisis , Ácido Peroxinitroso/química , Técnicas Biosensibles/instrumentación , Catálisis , Electroquímica , Electrodos , Concentración de Iones de Hidrógeno , Oxidación-Reducción , Óxidos/química
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