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.
Cabbage flower–like Ho
3+
/NiO nanostructure (CFL-Ho
3+
/NiO NSs) with significant electrocatalytic oxidation has been published for the first time. First, structure and morphology of CFL-Ho
3+
.../NiO-NSs have been described by XRD, SEM, and EDX methods. Then, CFL-Ho
3+
/NiO-NSs have been applied as a modifier for simultaneous electrochemical detection of methotrexate (MTX) and carbamazepine (CBZ). Functions of the modified electrode have been dealt with through electrochemical impedance spectroscopy (EIS). It has been demonstrated that the electrode response has been linear from 0.001–310.0 μM with a limit of detection of 5.2 nM and 4.5 nM (3 s/m) through DPV for MTX and CBZ. Diffusion coefficient (
D
) and heterogeneous rate constant (
k
h
) have been detected for MTX and CBZ oxidation at the surface of the modified electrode. Moreover, CFL-Ho
3+
/NiO-NS/GCE has been employed for determining MTX and CBZ in urine and drug specimens. Outputs showed the analyte acceptable recovery. Therefore, the electrode could be applied to analyze both analytes in drug prescription and clinical laboratories.
Graphical abstract
Electrochemical sensor based on bifunctional cabbage flower–like Ho
3+
/NiO nanostructures modified glassy carbon electrode for simultaneous detecting methotrexate and carbamazepine was fabricated
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
The presented research introduces a fabricated working electrode of cabbage flower-like Ho
3+
/NiO nanostructure (CFL-Ho
3+
/NiO NSs) as a glassy carbon electrode for the detection of flutamide, a ...prostate cancer drug, through a differential pulse voltammetry (DPV). A solvothermal technique was applied to produce the CFL-Ho
3+
/NiO NSs, which were subsequently characterized by Map, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and X-ray diffraction methods. Three various techniques of DPV, cyclic voltammetry, and chronoamperometry as well as multiple electrodes were employed to evaluate the electrochemical properties of flutamide. The reduction process of flutamide was tested by quantitative analysis at − 526 mV and pH 7.0. Diffusion coefficient of flutamide was assessed by chronoamperometry method in phosphate buffer solution (pH 7.0). Linear results were reported for the DPV in the range between 0.01 and 400.0 μM. Under optimized conditions, the range of linear responses was between 0.01 and 400.0 μM with the limit of quantification of 18.8 nM and limit of detection of 5.7 nM. The produced electrode was practically utilized to detect flutamide in flutanax tablets and real clinical urine samples, achieving successful results. The standard addition method was performed for the detection of flutamide present in urine samples using the modified electrode. The only urine treatment in this method was a simple dilution with supporting buffer.
Graphic abstract
Electrochemical sensor based on bifunctional cabbage flower-like Ho
3+
/NiO nanostructures modified glassy carbon electrode for detecting flutamide was fabricated
A convenient, low cost, and sensitive electrochemical method, based on a disposable graphene nanosheets (GR) and NiO nanoparticles modified carbon screen printed electrode (NiO/GR/SPE), is described ...for the simultaneous determination of dopamine (DA) and uric acid (UA). The modified electrode exhibited good electrocatalytic properties toward the oxidation of DA and UA. A peak potential difference of 150 mV between DA and UA was large enough to determine DA and UA individually and simultaneously. The anodic peak currents of DA were found to be linear in the concentration range of 1.0–500.0 μM with the detection limit of 3.14×10−7 M.
A screen-printed electrode (SPE) modified with the flower-like nanostructures of zinc oxide doped with terbium for forming FL-NS Tb
3+
/ZnO/SPE-modified electrode (electrochemical sensor) was ...provided for effective and rapid detection of sulfamethoxazole (SMX) and trimethoprim (TMP). Therefore, structure, composition, as well as the impact of process variables of the modified electrode, electrochemical response features of SMX and TMP, sensitivity of both simultaneous detections, and scan rate were examined in this research. According to the examinations, synergy of Tb and ZnO resulted in the promotion of the electrochemical reaction of SMX and TMP. Moreover, the difference in their oxidation peak potential was < 220 mV. In addition, the modified electrode linearly ranged from 0.001 to 900.0 μM, with the detection limit of 0.14 nM and 0.23 nM (S/N = 5) for SMX and TMP, respectively. Finally, it was found that this new FL-NS Tb
3+
/ZnO/SPE-modified electrode enjoys a broader smaller detection limits, linear range, and very good stability and reproducibility.
Graphical abstract
The current study aimed to modify a glassy carbon electrode with raspberry-like In
3+
/NiO hierarchical nanostructure as a novel and highly sensitive electrochemical sensor for effectively detection ...of allura red colorant, which was then characterized by techniques of energy-dispersive X-ray analysis, scanning electron microscopy, and X-ray diffraction. Electrochemical impedance spectroscopy, cyclic voltammetry, differential pulse voltammetry, and chronoamperometry were employed to calculate the oxidation peak current of colorant, resulting in linear range of 0.01–700 µM (
R
2
= 0.9999) and limit of detection of 4.1 nM. The developed modifier was practically recruited for the detection of allura red in phosphate buffer solution (pH 4) as well as the real samples of soft drinks, the results of which successfully showed a high performance for the electrode.
Graphical abstract
Electrochemical biosensor based on polypyrrole/La2O3 nanoparticles@snowflake-like Cu2S nanostructure composite and ds-DNA modified pencil graphite electrodes for detecting Idarubicin was fabricated.
...Display omitted
•La2O3 nanoparticles@snowflake-like Cu2S nanostructure composite was synthesized.•An electrochemical biosensor was fabricated with new nanostructure.•The modified biosensor achieves sensitive detection of idarubicin at nanomolar level.•This strategy is extended to practical assays of real samples.
Serious efforts have always been made to detect DNA molecules by fast, cost-effective, and susceptible instruments and clarify changes in DNA structure exposed to chemotherapy medicines. Accordingly, the present study endeavored to introduce a novel DNA biosensor fabricated by surface modification of pencil graphite electrodes using polypyrrole/La2O3 nanoparticles@snowflake-like Cu2S nanostructure composite, or PP/La2O3 NP@SF-L Cu2S NS composites, to detect ds-DNA molecules and Idarubicin (IDA). To prepare the proposed DNA biosensor, the ds-DNA was immobilized on the PP/La2O3 NP@SF-L Cu2S NS/PGE surface. IDA was detected electrochemically using differential pulse voltammetry (DPV). Subsequently, ultra-high sensitivity was reported for the biosensor of ds-DNA/PP/La2O3 NP@SF-L Cu2S NS/PGE towards the IDA so that the obtained limit of detection (LOD) was 1.3 nM with the linear range between 0.01 and 500.0 μM. The active reaction sites and admirable electrochemical activity associated with the nanocomposites were probably responsible for the excellent efficiency of the proposed biosensor, which accelerates electron transfer on the electrode surface and intensifies ds-DNA immobilization. The binding properties of IDA and DNA were investigated by molecular dynamic simulation (MDS), molecular docking (MD), and multi-spectroscopic analysis.
With the help of a hydrothermal approach in this study, we could provide flower-like nanostructures (NSs) of zinc oxide (ZnO) doped with Tb (FL-NS Tb
3+
/ZnO). Then, FL-NS Tb
3+
/ZnO morphology was ...investigated by energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and map analysis. The results revealed higher activity centers and porosity of this nanocomposite, which were followed by acceptable electrochemical function. Hence, it can be utilized for fabricating an electrochemical sensor with an appropriate response for the simultaneous determination of kynurenic acid (KYN) and tryptophan (TRP). However, as compared with the modified carbon paste electrode (FL-NS Tb
3+
/ZnO/CPE), the bare carbon paste electrode (BCPE) exhibited a weak response toward KYN and TRP but the modified electrode was followed by a high current response for KYN and TRP at a potential 0.35 and 0.809 V. Therefore, cyclic voltammetry (CV) was applied in optimal experimental conditions to study the electrochemical behaviors of KYN and TRP over the surface of the proposed modified electrode. Moreover, we used differential pulse voltammetry (DPV) for quantitative measurements. It was found that this new modified electrode linearly ranged from 0.001 to 700.0 μM, with detection limits of 0.34 nM and 0.22 nM for KYN and TRP, respectively. In addition, KYN and TRP in real samples can be analyzed by this sensor, with a recovery of 97.75%−103.6% for the spiked KYN and TRP in real samples.
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.
