Metal organic frameworks (MOFs) are considered as a group of compounds, either metal ions or clusters, harmonized with organic ligands to form one or some dimensional structures. In addition to ...resilient bonds between inorganic and organic units, reticular synthesis creates MOFs, accurate selection of constituents of which can produce high thermal and chemical stability and crystals of ultrahigh porosity. Other solids have not shown the same accuracy normally used in chemical modification and even the capability of increasing their metrics with no modification of the underlying topology. With shape of building units and chemical compositions multiplying based on specific structures, MOFs might result in compounds that propose a synergistic mixture of features. This study presents up to date advances in both synthesis methods of MOFs and structural characteristics. Furthermore, the use of MOFs in different fields such as the removal of absorption and separation of toxic substances from gas and liquid, catalysts, a variety of sensors, storage of clean energies and environmental applications, medical and biological applications, and optoelectronic equipment is included.
•Metal-organic frameworks (MOFs) have been currently recognized as a considerable group of porous compounds.•MOFs can be used in various areas and has some outrival in chemical recognition and separation.•The synthesis along with the potential uses of MOFs were provided in this article.
The current effort introduces a facile construction of peony-like CuO:Tb3+ nanostructure (P-L CuO:Tb3+ NS), whose characterization was determined via techniques of X-ray diffraction, scanning ...electron microscopy and energy dispersive X‐ray spectroscopy. We investigated ofloxacin, pefloxacin and gatifloxacin oxidation electrochemically on P-L CuO:Tb3+ NS-modified glassy carbon electrode (P-L CuO:Tb3+ NS/GCE), the results of which revealed the irreversible oxidation of drugs through a two-electron oxidation process. An admirable resolution was found for this modified electrode between voltammetric peaks of ofloxacin, pefloxacin and gatifloxacin, suggesting its appropriateness for simultaneous detection of these drugs in pharmaceutical media. In addition, our nanostructure synergistically influenced the electro-catalytic oxidations of these three compounds. Differential pulse voltammetric measurements of ofloxacin, pefloxacin and gatifloxacin through our sensor showed a limit of detection of 1.9, 2.3 and 1.2 nM a as well as a linear dynamic range between 0.01 and 800.0 μM in phosphate buffered solution (0.1 M, pH = 6.0), respectively. Moreover, as-fabricated sensor could successfully co-detect these drugs in real serum and tablets specimens. In addition, since we use animal foods such as milk it is very important to detect their fluoroquinolone residues. For this purpose, the proposed sensor was tested to determine the residues of ofloxacin, pefloxacin and gatifloxacin in milk.
Electrochemical sensor based on peony-like CuO:Tb3+ nanostructure (P-L CuO:Tb3+ NS) modified glassy carbon electrode for simultaneous detecting of ofloxacin, pefloxacin and gatifloxacin was fabricated. Display omitted
•Peony-like CuO:Tb3+ nanostructure were characterized by EDX, XRD and SEM.•P-L CuO:Tb3+ NS was used for modified glassy carbon electrode.•This modified electrode was used for the simultaneous determination of ofloxacin, pefloxacin and gatifloxacin.•Modification improved the sensitivity and detection limit of the method.
A glassy carbon electrode (GCE) was modified with cerium-doped ZnO nanoflowers (Ce-ZnO/GCE) to obtain a sensor for direct simultaneous detection of the cancer drugs epirubicin and methotrexate. XRD, ...SEM and EDX techniques were used to characterize their morphology and structure. Electrochemical impedance spectroscopy was applied to characterize the electrochemical features of the modified GCE. The experimental conditions were optimized. Diffusion coefficients and heterogeneous rate constants were determined for the oxidation of epirubicin. The differential pulse voltammetric response to epirubicin has a peak near 0.7 V (vs. Ag/AgCl at a scan rate of 50 mV s
−1
) and is linear in the 0.01 to 600 μM concentration range, and the detection limit is 2.3 nM (S/
N
= 5). The differential pulse voltammetric response to methotrexate has a peak near 0.75 V (vs. Ag/AgCl and the same scan rate) and is linear in the 0.01 to 500 μM concentration range, and the detection limit is 6.3 nM (S/
N
= 5). The method was applied to the simultaneous determination of epirubicin and methotrexate in pharmaceutical injections and in spiked diluted blood specimens.
Graphical abstract
Schematic of an electrochemical sensor based on Ce-doped ZnO nano-flowers modified glassy carbon electrode for detecting epirubicin
We could successfully fabricate a new composite of La2O3 nanoparticles@snowflake-like Cu2S nanostructure (La2O3 NP@SF-L Cu2S NS composite) for simultaneous detection of hydroquinone (HQ), catechol ...(CT), and resorcinol (RS). Field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscope (EDX) and X-ray diffraction (XRD) were used to characterize the constructed La2O3 NP@SF-L Cu2S NS composites. The presence of HQ, CT and RS was simultaneously detected on the surface of modified La2O3 NP@SF-L Cu2S NS composites because of unique properties such as large surface area, high electrical conductivity and potent catalytic activity, with the appearance of three distinctive peaks. Moreover, differential pulse voltammetric (DPV), chronoamperometry (CHA) and cyclic voltammetric (CV) were also employed to determine the electrocatalytic profile of CT, HQ and RS on electrode modified with the nanocomposite (La2O3 NP@SF-L Cu2S NS/GCE). There was a significant elevation in the HQ, CT and RS oxidation currents when compared to those on both bare and modified electrodes. The peak of the catalytic current was directly variable based on the concentrations of HQ, CT and RS (0.66 to 266.6 μM), respectively. Further, the limit of detection (LOD) was calculated to be 0.056 μM, 0.058 μM and 0.059 μM for all HQ, CT and RS, respectively. Acceptable outcomes were achieved for the applicability of La2O3 NP@SF-L Cu2S NS/GCE in detecting HQ, CT and RS present in real specimens.
In this work, the polypyrrole (PPy) film was deposited on the surface of mild steel electrode by cyclic voltammetry. Then, the electrochemical impedance spectroscopy (EIS) measurements were performed ...on the PPy coated mild steel samples which were exposed to 0.5M HCl solution. After a brief review of the literature, a new equivalent circuit (EC) was proposed for the modeling of EIS data. It was shown that the proposed EC can be simplified to each of EC1, EC2 and EC3 circuits describing the corrosion behavior of PPy coated mild steel in each of short-term, medium-term and long-term immersion periods, respectively. Then, the suggested model was employed to investigate the effects of the scan rate and the cycle number of polymerization process on the corrosion protection of the PPy coated mild steel. Among the three types of PPy coatings synthesized at the scan rates of 50, 100 and 200mV/s the second one (100mV/s) was proved to be the optimum coating against corrosion. This is the result of the competition of two opposing effects: thickness reduction and porosity decrement. The coating prepared during 80cycles showed the best performance against corrosion of mild steel during long immersion times among the coatings synthesized with different cycle numbers (10, 20, 40 and 80cycles). This was due to both the higher thickness of PPy coating and the better blockage of coating pores. FT-IR technique was employed to characterize the PPy films.
•The corrosion behavior of polypyrrole (PPy) coated mild steel exposed to HCl solution was investigated.•A new equivalent circuit (EC) was proposed for modeling the EIS data.•The EC was simplified to one of three ECs corresponding to each of short-term, medium-term or long-term immersion periods.•Mild steel coated with PPy deposited at the scan rate of 100mV/s and 80 cycles showed the best corrosion performance.•An increase of the scan rate leads to decrease of two opposing factors: the thickness and the porosity of PPy coatings.
This study designed a simplistic, efficient, and greener procedure to synthesize CeO2-CNTs. The analysis of structural and morphological characteristics of nano-composites has been done with regard ...to different procedures (e.g., EDX, XRD, & FESEM). In addition, simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and acetaminophen (AC) has been examined at the modified glassy carbon electrode with CeO2-CNTs nano-composites. The surface area and electron transfer speed of the interplay between neuro-transmitters and electrode may be efficiently enhanced due to the existence of CeO2 nano-particles on CNTs surfaces. Moreover, electro-chemical behavior of electrodes has been dealt with by differential pulse voltammetry (DPV), impedance analysis (EIS), and cyclic voltammetry (CV). Acceptable linear response of AA, DA, UA and AC respectively have been ranged 0.01–900.0 μM, 0.01–700.0 μM, 0.01–900.0 μM, and 0.01–900.0 μM with determination limits (S/N = 3) of 3.1 nM, 2.6 nM, 2.4 nM and 4.4 nM. Ultimately, this procedure was used with successful results for determining AA, DA, UA and AC in real specimens, which suggested probable uses in other sensing studies.
Electrochemical sensor based on CeO2 nanoparticles-decorated CNTs modified glassy carbon electrode for simultaneous detecting ascorbic acid (AA), dopamine (DA), uric acid (UA) and acetaminophen (AC) was fabricated. Display omitted
•CeO2 nanoparticles-decorated CNTs were synthesized with a microwave solvent-free method.•CeO2 nanoparticles-decorated CNTs was used for modified glassy carbon electrode.•This modified electrode was used for the simultaneous determination of AA, DA, UA and AC.
This study substantially synthesized the β-type MnO2 nano-flowers assembled by the hierarchical nano-sheets using a simplified hydro-thermal procedure. According to the FESEM images, MnO2 nano-flower ...exhibited diameter of ∼800 nm and fabricated with a lot of irregular sheets as a petal-like structure with thickness of several nano-meters. Therefore, the study focused on the construction of an electro-chemical sensor to simultaneously determine theobromine (ThB), theophylline (ThP), as well as caffeine (CaF) on the basis of the β-type hierarchical structure of the MnO2 nano-flowers (βH-MnO2-NF) modified electrode (βH-MnO2-NF/GCE). Analysis showed an acceptable linear association between the oxidation peak current and ThB, ThP and CaF concentration within the ranges between 0.01 and 320.0 μM with a limit of detection (LOD) equal to 8.7, 5.9, and 10.1 nM (S/N = 3), respectively. Additionally, this study intended to investigate ThB, Thp and CaF bio-availability in the five commercially available brands of the chocolate products and drug.
Electrochemical sensor based on β-MnO2 nanoflower modified glassy carbon electrode for simultaneous detecting theobromine, theophylline and caffeine was fabricated. Display omitted
•Petal-like MnO2 nanostructure were synthesized and characterized by EDX, XRD and SEM.•Petal-like MnO2 nanostructure was used for modified carbon paste electrode.•This modified electrode was used for the simultaneous determination of 3 methylxanthines.
It is crucial to design fast, sensitive and affordable deoxyribonucleic acid (DNA) recognition instruments, and elucidate changes in DNA structure, for studying the interaction between DNA and ...chemotherapy drugs. Therefore, a DNA biosensor, based on a carbon paste electrode (CPE), modified with raspberry‐like indium(III)/nickel oxide hierarchical nano‐structures (In3+/NiO RLHNSs) was constructed. An electrochemical readout should then give information on the interactions between anticancer drugs and double‐stranded (ds)‐DNA. The morphology as well as the electrochemical description of this new biosensor is described. Based on experimentally determined optimal conditions, ds‐DNA modified with In3+/NiO RLHNSs/CPE was used to evaluate the binding interaction of nilotinib, as an anti‐cancer drug, with DNA through differential pulse voltammetry (DPV), UV‐Vis spectroscopy, viscosity measurements and a computational docking process. The analyses indicated the linearity of the guanine oxidation signal at nilotinib concentration is given between 0.01 and 50.0 μm, with the limit of detection (LOD) equal to 0.62 nm. Additionally, the equilibrium constant (K) for the binding was determined to 1.5×104 m−1. Through the quantitative measurement of nilotinib in serum samples with a high recovery rate of 101.3–98.0 %, the applicability of this approach was demonstrated. As a whole, this DNA biosensor may be promising for various bio‐interactions.
A DNA biosensor based on a carbon paste electrode, modified with raspberry‐like indium(III)/nickel oxide hierarchical nano‐structures was constructed and characterized. It can be used to electrochemically determine the concentration of nilotinib and has been tested for use in real serum samples.
•Lanthanum doped fern like CuO nanoleaves were characterized by FT-IR, EDX, XRD, XPS, SEM and TEM.•La3+-CuO/MWCNT was used as the modifier.•This modified electrode was used for the simultaneous ...determination of tramadol and acetaminophen.•Modification improved the sensitivity and detection limit of the method.
An innovative and adept single-stage approach was created to synthesis lanthanum doped fern like CuO nanoleaves (La3+-CuO fern-like nanoleaves). The morphology and structure of fern like La3+-CuO nanoleaves are characterized by using the FT-IR, EDX, SEM, XPS and TEM techniques. Drop casting fern-like La3+-CuO nanoleaves suspension on MWCNTs/GC was used to fabricate the La3+-CuO/MWCNTs nanocomposites modified glassy carbon (GC) electrode. For electrochemical behavioral assessment of tramadol, differential pulse voltammetric analysis (DPV) and cyclic voltammetry (CV) was implemented and the oxidation performance on MWCNTs/GC, La3+-CuO/MWCNTs/GC and bare GC was compared. The obtained results indicate that amalgamation of fern-like La3+-CuO nanoleaves and multiwall carbon nanotubes will entail a significant improvement of sensor sensitivity. A limit detection of 0.014 μM within a linear range of 0.5–900.0 μM was determined for obtaining the quantitative tramadol detection. Moreover, this sensor proved favorable to simultaneously determine tramadol and acetaminophen. Additionally, great sensitivity and stability was shown by the fabricated sensor which will be beneficial for tramadol and acetaminophen clinical assay.
Electrochemical sensor based on woolen ball-shaped La3+/TiO2 nanostructure modified screen printed electrode for detecting of ascorbic acid (AA), dopamine (DA), acetaminophen (AC) and tryptophan ...(Try) was fabricated.
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•WB-S La3+/TiO2-NS were synthesized and characterized by EDX, XRD and SEM.•WB-S La3+/TiO2-NS was used for modified screen printed electrode.•This modified electrode was used for the simultaneous determination of AA, Da, Ac and Try.•Modification improved the sensitivity and detection limit of the method.
Woolen ball-shaped La3+/TiO2 nanostructure (WB-S La3+/TiO2-NS) was constructed, followed by specification using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Cyclic voltammograms of this new nanocomposite sensor provided distinct and sharp oxidation peaks for the study analytes, including ascorbic acid (AA), dopamine (DA), acetaminophen (AC) and tryptophan (Try). An effective electron-mediated response of the nanosensor was determined with broad peak separations of 0.2 for AA-DA, 0.2 for DA-AC, and 0.31 V for AC-Try. According to differential pulse voltammograms, the nanostructure electrode could simultaneously detect AA, DA, AC and Try, with linear ranges from 0.001 to 900.0 μM, with the limit of detection of 0.63 ± 0.01, 0.51 ± 0.02, 0.72 ± 0.03 and 0.84 ± 0.04 nM, sequentially. Further, the analytical applicability of WB-S La3+/TiO2-NS/SPE was confirmed by sensing AA, DA, AC and Try in real human serum samples.
