جستجوی مقالات مرتبط با کلیدواژه "metal-organic frameworks" در نشریات گروه "شیمی"

Metal-Organic Frameworks (MOFs) offer significant potential as effective drug carriers due to their porous architecture, diverse chemical makeup, and adaptable properties. Zeolitic Imidazolate Frameworks (ZIFs) are significant nanocarriers due to their excellent biocompatibility and structural integrity. the toxicity exhibited by most ZIFs restricts their use as biomedicine. This study encapsulates the widely used chemotherapy drug doxorubicin (DOX) within biocompatible ZIF-8 and ZIF-7 nanoparticles, to develop an intelligent drug delivery system sensitive to changes in PH levels. The crystalline ZIFs with loaded DOX were subjected to systematic characterization using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and UltraViolet-Visible (UV-Vis) spectroscopy. Additionally, BET studies confirmed that surface modification had negligible influence on the surface area and distribution of pore size. Furthermore, kinetic and isotherm investigations were carried out, and experiments were conducted to examine the drug release dependency on pH. The results revealed a remarkable pH-responsive release, with ZIF-8 demonstrating a cumulative amount of 80% at pH 5.5, starkly contrasting the negligible release observed at pH 7.4. This unique pH-responsive behavior was attributed to the regulated degradation of the ZIF-8 framework in an acidic environment typically found in tumor sites. On the other hand, ZIF-7 exhibited negligible pH-responsive drug release with a higher chemical stability. Toxicity tests conducted on MCF-7 breast cancer cells highlighted the enhanced effectiveness of DOX-loaded ZIF-8 in cancer therapy compared to DOX alone. Our findings demonstrate the significant potential of ZIF-8 as a custom nanocarrier for targeted and extended delivery of anticancer drugs, activated specifically by the acidic environment of tumors. These insights are vital for developing future MOF-based drug delivery systems tailored for cancer treatment.

Lithium is one of the critical elements in the development of industries, and its amount in seawater and brines (2.5×1011 tonnes) is estimated to be about 16,000 times more than land-based resources. However, the low lithium concentration in seawater (0.17 ppm) requires an efficient and selective method of lithium extraction. Although metal-organic frameworks (MOFs) are widely utilized for removing or extracting heavy metals from seawater, they have not been extensively employed for lithium extraction from such sources. This research used a bimetallic MOF-based adsorbent (MnO2@Co/Zn ZIF) to extract lithium ions from the solution. The effects of Li+ concentration and contact time on adsorption were investigated. Based on kinetic studies, the pseudo-second-order model adequately represents the kinetic behavior of lithium adsorption. The thermodynamic study demonstrated lithium adsorption with MnO2@Co/Zn ZIF is endothermic, spontaneous, and physisorption. The adsorption process fitted well with the Freundlich isotherm (R2=0.994), and this isotherm showed the maximum adsorption capacity at room temperature to be 71.43 mg/g. The desorption process was carried out with an HCl solution and showed that MnO2@Co/Zn ZIF has excellent desorption ability. In addition, it was demonstrated that the adsorbent could be used for lithium adsorption after three cycles of regeneration. Moreover, MnO2@Co/Zn ZIF is a viable candidate for recovering large amounts of lithium ions from solutions, based on the results.

This study presents the synthesis of Zn/La³⁺-based metal-organic frameworks (MOFs) using a co-precipitation assisted microwave method. Characterization through SEM and TEM revealed uniform nanoparticles around 80 nm. FT-IR spectroscopy confirmed the presence of key functional groups. Dynamic light scattering (DLS) showed highly uniform particle sizes. In vitro release studies of captopril from Zn/La³⁺/MOFs demonstrated a 41% release rate over 300 min, compared to 64% for pure captopril. Encapsulation within the MOF matrix ensured controlled and sustained drug release, with the first -order kinetic model fitting best. These Zn/La³⁺/MOFs show promise for enhanced and controlled drug delivery systems.

Metal-organic frameworks (MOFs) have become a highly promising porous material for the detection of cancer biomarkers due to their special characteristics, such as permanent porosity and tuneable pore size. Such advantages make MOFs well-suited for use in biosensing applications. In this review, a comprehensive overview of the use of MOFs in the electrochemical detection of bioorganic materials has been provided. We begin by discussing the adjustable surface areas and porosity of MOFs, which are crucial for their applicability in biosensing. The ability to control the porosity of MOFs allows for the efficient capture and detection of specific biomarkers. Furthermore, the presence of functional sites on MOF surfaces enhances their sensitivity and selectivity towards target molecules. In the next step, we investigated different biosensors for the detection of cancer biomarkers that have used MOF to improve their performance. These biosensors utilize the unique properties of MOFs to selectively bind and detect specific biomarkers associated with different types of cancer. The high sensitivity and selectivity of these biosensors make them promising tools for early cancer diagnosis and monitoring.

Copper benzene 1,3,5-tri carboxylates are widely used in research due to their numerous advantages. With abundant resources, excellent catalytic activity, and relatively simple synthetic procedures, Cu MOFs are ideal for activating starting materials and creating complex structural designs. The tunable conditions promote useful reactions such as oxidation, click chemistry, and Friedel-Crafts alkylation. All these properties make Cu MOFs an excellent choice for scientific research. This review provides an overview of this rapidly evolving research field, highlighting novel Cu3(BTC)2 synthesis strategies and Cu3(BTC)2 applications such as electrochemical sensing and metal ion extraction, energy storage, drug delivery, and its role as a catalyst.

Metal-organic frameworks as porous materials are highly advantageous over other porous carriers like mesoporous silica or zeolites. They provide advantages for biomolecule release and their adsorption characteristics offer many opportunities. Thus, they present high applicability in medicine and biology. Metal-organic frameworks (MOF) possess appealing structures and usages including high surface area, homogenous structured nanoscale cavities, and excellent thermal stability. Therefore, they can be a new sorbent alternative for preparing samples. In the present study, a MOF fiber application for solid-phase microextraction is reported. The MOF fiber is in nano size and has a high surface area. 3D and oriented organizations of MOF materials are vital so that they may be utilized as the fiber coating for microextraction in solid-phase for volatile substances in the medicinal herbs. In order to make Cu-based MOFs into three-dimensional hierarchical nanoarray structures, a coordination replication approach is created. To this end, Cu(OH)2 nanorod arrays are used as a sacrificial template. Cu(OH)2 nanorod arrays serving as Cu origin provided coordination with organic ligands for forming MOF crystals and 3D substrate for supporting Cu-based MOF growth. Following the presentation of the fiber, essential oils of Satureja hortensis L were determined using GC-MS. Ease of use, shorter analysis period, inexpensive tools as well as a high rate of recovery are advantages of the proposed approach compared to ordinary analysis approaches.

3-substituted indole derivatives as a key intermediate for the synthesis of complex indole alkaloids have been synthesized by Yonemitsu condensation reaction between indole, dimedone, and benzaldehyde. This reaction was carried out using copper benzene-1,3,5-trioxylate acid catalyst for the first time. In addition to its acidic properties, the aforementioned catalyst has a 3D network, and the existence of these holes can help to advance the reaction. This reaction proceeds smoothly and has achieved good yields (80-90%) by using water as a green solvent at 60°C. The investigations show that the electron-withdrawing groups on the aldehyde compound perform the reaction at a higher speed, which is completely consistent with the presented mechanism and the presence of the carbocation. This modified reaction has numerous advantages, including high efficiency, short reaction time, low reaction temperature, and the use of water as a green solvent.

Nowadays metal-organic frameworks with multiple luminescent centers are very fascinating as multifunctional luminescent material because of their luminescence properties, which could be systematically tuned by deliberate use of organic ligands and metal ions. In this research, we explored a microporous mixed-ligand MOF for highly selective and sensitive detection of metal ions. A two-fold interpenetration pillared-layer amine/imine-functionalized MOF known as TMU-16-NH2, [Zn2(NH2-BDC)2(4-bpdh)]·3DMF, have been synthesized via a mixed ligand approach using amino-1,4-benzenedicarboxylate (NH2-BDC) and 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh) under solvothermal condition. Sensor TMU-16-NH2 exhibits Al3+-selective TURN-ON and Fe3+-selective TURN-OFF type fluorescence emission responses, for which the electrostatic interaction between Fe3+ and Al3+ ions and the inner surface of the micropores may play a critical role. Moreover, the sensor TMU-16-NH2 shows significantly color change from light yellow to orange and colorless with the addition of Fe3+ and Al3+ ions, respectively, which is distinguished by naked-eye. More significantly, the remarkable quenching and enhancing effects of TMU-16-NH2 for Fe3+ and Al3+ possess the advantages of good selectivity, fast response time (<1min), low-cost, as well as very low detection limits of 0.7 and 0.09 µM for Fe3+ and Al3+, respectively. Interestingly, the probe exhibits high sensitivity for Fe3+ and Al3+ ions, which is far below WHO's acceptable limit in drinking water.

In this study, an amide-functionalized metal-organic framework, namely TMU-24 was selected to adsorb Co(II) from wastewater with an adsorption capacity of 500 mg. g-1 in less than 20 minutes in neutral pH (pH=7). The effect of diverse parameters such as adsorbent dosage, competitive ions, and contact time on the adsorption process was investigated to find the optimal amounts of them. Also, the modeling calculations demonstrated that this compound obeys Pseudo-Second-order and Langmuir models with correlation coefficients of R² = 0.9996 and R² = 0.9761, respectively. So, the adsorption mechanism could be monolayer chemical interaction according to these models. Moreover, PXRD patterns of the framework before the adsorption procedure and after that revealed that the MOF could keep its structure, suggesting the stability of the framework. So, we can claim that our proposal adsorbent is a promising candidate for cobalt(II) removal from pollutant water.

In this report, an IRMOF-3 was synthesized via a solvothermal method and then used as support for stabilizing Cu(II) ions. Characterization methods such as FT-IR, XRD, SEM, and BET were employed to analyze produced Cu@IRMOF-3, demonstrating that the suggested catalyst effectively conserved its structure throughout the synthesis processes. The FT-IR results indicate that the presence of the -NH2 group in the structure of the MOF helped stabilize the Cu(II) ions. The manufactured catalyst was used to prepare polyhydroquinoline derivatives which showed superior results.

Over the last decade, the usage of metal-organic frameworks (MOFs) for electrochemical applications has grown in popularity. The sensitivity of amperometric sensors, which use currently as the sensing response for the targeted analyte is one of the most often encountered electrochemical sensing systems. Electrocatalysts with high reaction rates and the ability to selectively react with the intended analyte are generally required. Because electrochemical reactions may only occur on the surface of an electrode, depositing or immobilizing the electrocatalyst on the surface of an electrode to produce a modified electrode is a typical technique for constructing the active electrode of an amperometric sensor. As we know, multiple chemical functionalities can be incorporated into the entire pore structure of MOFs with different synthetic routes without losing much porosity. However, because most MOFs are not chemically stable in water, and most electrochemical sensing systems require the use of aqueous electrolytes, water stability of MOFs becomes one of the primary issues for MOF usage in electroanalysis. Only lately have significant attempts been made to manufacture MOFs utilizing biomimetic mineralization methods, in which biomolecules are employed as crystallization and guiding agents to design a variety of MOFs. MOF-based particles containing biomolecules such as enzymes, proteins, peptides, cells, DNA, and viruses have been synthesized using this technique. This review summarizes recent developments of MOF-‎biomolecule composites with special emphasis on preparative techniques and the synergistic effects of biomolecules and MOFs. The applications of MOF-‎biomolecule composites in electrosensing are presented as well.

Continual and excessive accumulation of coloured contaminants discharged into various water bodies by many industries (textile, leather, paper, dyestuff and plastic) in our environment leading to direct and indirect contamination and pollution of our water system endanger human and aquatic lives. The thermal and photostability nature of these coloured contaminants which makes them difficult to be eliminated from our water system is of great concern. Researchers are continually putting massive attention on the possibilities of improving existing methods and technologies, developing novel strategies, and bring about solutions to subdue these dye-related water contamination problems which will be economically and environmentally friendly. One of the most sustainable technology or method employed in the decontamination and purification of coloured wastewater is adsorption. It possesses several advantages as it has simple and easy design of operation and is highly economical. Metal-organic frameworks (MOFs) play substantial roles under this application as a new class of porous adsorbents that are characterized by a highly crystalline molecular structure and relatively large surface area which is a significant parameter to be considered in adsorption processes. They are also recommended as a good choice of sorbents employed in wastewater purification technologies as a result of their tunable features. This research study aimed at providing a comprehensive review of recent studies on the adsorptive use of MOFs for the removal of these developing organic pollutants from wastewater.

In this report, a new aptamer-based assay was presented reporting the electrochemical aptasensing for sensing tyrosinamide (Tyr-NH2). This strategy was relied on unbeatable conformational flexibility and specific recognition of aptamers. The tyrosinamide aptamer (Tyr-NH2-aptamer) was immobilized onto the metal-organic frameworks/silver nanoparticles modified glassy carbon electrode and hexacyanoferrate was selected as a probe to monitor interface variations during modification of the electrode and the aptamer conformational change generated by the Tyr-NH2 binding. Results showed that measurements by using electrochemical impedance spectroscopy had linear with the Tyr-NH2 concentrations in range of 0.01-0.25 nM and 0.25-1.15 nM. Detection limit of this system was found to be 2.3 pM. This method was also used to the Tyr-NH2 detection in serum samples successfully. Remarkable simplicity, ease of use and low-cost, make methodology as sensitive analytical system for sensing of the Tyr-NH2 that can be miniaturized. This strategy offers some promising advantages in reliable detection of the Tyr-NH2, which may be helpful in the routine analysis.