► A new electrocatalyst, AuNPs-SH-SiO2@Cu-MOF was fabricated and used as a modifier. ► The modified electrode was used as an electrochemical sensor for hydrazine. ► The sensor showed good ...electroanalytical performance toward the hydrazine detection.
A new electrocatalyst, Au-SH-SiO2 nanoparticles immobilized on the metal-organic frameworks (MOFs) was synthesized and characterized by scanning electron microscopy (SEM), the transmission electron microscopy (TEM) and cyclic voltammetry (CV). The prepared electrocatalyst immobilized onto the surface of a glassy carbon electrode (GCE) to obtain Au-SH-SiO2@Cu-MOF/GCE. The sensor showed good electrocatalytic activity toward the oxidation of hydrazine in the neutral phosphate buffer solution (pH 7.0). The kinetic parameters such as the electron transfer coefficient (α) and the catalytic rate constant (kcat) for the oxidation of hydrazine were determined. The diffusion coefficient (D) of hydrazine in solution was also calculated by chronoamperometry. The potential application of the sensor was demonstrated by applying to the analytical determination of hydrazine concentration. Our results showed that the sensor had good electrocatalytic activity toward determination of hydrazine and exhibited a low detection limit (0.01μM), a wide linear range (0.04–500μM), and high sensitivity (0.1μAμM−1) as well as good stability and repeatability. The sensor has been successfully applied to determine hydrazine in water samples with good accuracy and precision.
Designing an antibacterial agent with a suitable water vapor permeability, good mechanical properties, and controlled antibiotic release is a promising method for stopping bacterial infection in ...wound tissue. In this respect, this work aims to prepare novel flexible polymeric hydrogel films via integrating UiO-66 into the polymeric carboxymethyl cellulose (CMC) hydrogel for improving the mechanical and antibiotic release performances. First, we performed a green hydrothermal synthetic method to synthesis UiO-66 and followed by encapsulating Tetracycline (TC) through immersion in its aqueous solution. Also, the casting technique was utilized to integrate different concentrations of the TC-encapsulated UiO-66 (TC@UiO-66, 5% to 15%) in the polymeric CMC matrix (CMC/TC@UiO-66) cross-linked by citric acid and plasticized by glycerol. The release performance showed a low initial burst release with a controlled release over 72 h in the artificial sweat and simulated wound exudate (PBS, pH 7.4) media. The in vitro cytotoxicity and antibacterial activity results revealed a good cytocompatibility toward Human skin fibroblast (HFF-1) cells and a significant activity against both E. coli and S. aureus with 1.3 and 1.7 cm inhibition zone, respectively. The obtained results recommend CMC/TC@UiO-66 films as a potential antibacterial wound dressing.
In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SA-DSPE) was developed. The new method was based on the dispersion of the sorbent into ...the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by flame atomic absorption spectrophotometer. Under the optimized conditions, the detection limit for lead and cadmium ions was 1.2 μg L(-1) and 0.2 μg L(-1), respectively. Furthermore, the preconcentration factor was 299.3 and 137.1 for cadmium and lead ions, respectively. SA-DSPE was successfully applied for trace determination of lead and cadmium in fruit (Citrus limetta, Kiwi and pomegranate) and water samples. Finally, the introduced sample preparation method can be used as a simple, rapid, reliable, selective and sensitive method for flame atomic absorption spectrophotometric determination of trace levels of lead and cadmium ions in fruit and water samples.
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•The b-N-TiO2 photocatalyst was synthesized as a highly active and recyclable catalyst.•The narrowed bandgap of 2 eV extends the photoresponse to visible light region.•The synergy of ...N, Ti3+ codoping and oxygen vacancies promoted the visible absorption.•The degradation efficiency of CIP over b-N-TiO2 was two times more than N-Ti02.•The b-N-TiO2/LED process was efficient in toxicity reduction of CIP.
In this work, the photocatalytic degradation of ciprofloxacin (CIP) by black Ti3+/N-TiO2 under visible LED light irradiation (b-N-TiO2/LED) was studied for the first time. Characterization of the prepared photocatalyst was performed by XRD, UV–Vis DRS, FE-SEM, EDS, HRTEM, and BET techniques. The b-N-TiO2 nanoparticles with high surface area of near 100 m2 g−1 and narrow band gap of 2.0 eV, exhibited a remarkable photocatalytic performance on the degradation (100 %) and mineralization (82 %) of CIP under visible LED light irradiation. The maximum degradation was found at reaction time = 70 min, initial CIP concentration = 0.5 mg L−1, pH = 6.7, and catalyst dosage = 0.43 g L−1. Based on the results, both the hole (h+) and hydroxyl radical (OH) played a major role than the superoxide radical (O2−) in CIP degradation. Although common coexisting anions in water had a slight negative effect on CIP degradation; humic acid (HA), especially in higher amounts, showed a considerable inhibitory effect on degradation process. Besides, the intermediates of CIP degradation were ultimately transformed into simple compounds. Accordingly, toxicity assessments revealed that the treatment of CIP solution by b-N-TiO2/LED process remarkably resulted in diminished toxicity compared to the untreated controls. The energy utilized in this study was far less than that used in other studies. Moreover, we found that b-N-TiO2 had desirable stability and can be reused for more than five runs of experiments. Collectively, based on our findings, the b-N-TiO2/LED process is a promising, low cost and feasible candidate can be used for degradation and mineralization of antibiotics like CIP in real water samples.
Recent progress in the nanocarriers synthesis allows the utilization of dual-drug delivery systems (DDDS) that encapsulate two drugs to enhance treatment effects. In this regard, novel pH-responsive ...double core-shell magnetic nanoparticles (NPs) via the Ugi multicomponent reaction (Ugi-MCR) strategy were developed for simultaneously delivering of doxorubicin (DOX) and methotrexate (MTX) as anticancer drugs. The prepared materials were characterized by XRD, NMR, FT-IR, VSM, TGA, SEM, and DLS analysis. In-vitro drug loading and release behaviors were studied. DOX and MTX successfully loaded in the prepared nanocarriers that exhibited pH-controlled release of drugs in a sustained manner. The cytotoxicity study indicated that blank nanocarrier against MCF7 cell lines has a cytocompatible future; however, the co-administration of MTX with DOX has notable cytotoxicity to the MCF7 cell lines due to the formation of pseudo peptide skeletons in nanocarrier. According to the results, the prepared dual anticancer drug-loaded pH-responsive double core-shell magnetic NPs have the potential for anticancer therapy.
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•Fe3O4@SiO2@Tann was successfully synthesized via the Ugi multicomponent reaction strategy.•DOX and MTX were loaded in the Fe3O4@SiO2@Tann double core-shell magnetic nanoparticles.•The DOX and MTX release rate at pH 5 were significantly higher than pH 7.4.•The co-administration of MTX with DOX has notable cytotoxicity to the MCF7 cell lines.
In this study, a magnetic metal–organic framework was synthesized simply and utilized in the dispersive magnetic solid‐phase extraction of five phthalate esters followed by their determination by gas ...chromatography with mass spectrometry. First, MIL‐101(Cr) was prepared hydrothermally in water medium without using highly corrosive hydrofluoric acid, utilizing an autoclave oven heat supply. Afterward, Fe3O4 nanoparticles were decorated into the matrix of MIL‐101(Cr) to fabricate magnetic MIL‐101 nanocomposite. The nanocomposite was characterized by various techniques. The parameters affecting dispersive magnetic solid‐phase extraction efficiency were optimized and obtained as: a sorbent amount of 15 mg; a sorption time of 20 min; an elution time of 5 min; NaCl concentration, 10% w/v; type and volume of the eluent 1 mL n‐hexane/acetone (1:1 v/v). Under the optimum conditions detection limits and linear dynamic ranges were achieved in the range of 0.08–0.15 and 0.5–200 μg/L, respectively. The intra‐ and interday RSD% values were obtained in the range of 2.5–9.5 and 4.6–10.4, respectively. Ultimately, the applicability of the method was successfully confirmed by the extraction and determination of the model analytes in water samples, and human plasma in the range of microgram per liter and satisfactory results were obtained.
Metal-organic frameworks are novel adsorbents that have been widely used in recent years. The main properties of this emerging adsorbent include high specific surface area, significant porosity, ...regular structure and adjustable cavities. The main objective of this study was ZIF-8 synthesis with cubic structure, functionalization with ethylenediamine and evaluation for arsenic adsorption from aqueous environments. All the experiments were carried out in batch conditions. Main variables including pH, initial arsenic concentration, adsorbent dosage and contact time were evaluated in this work. In this study, Design of Experiment software was used for experimental runs order arrangement and better understanding of the variables effects on the process. The BET results showed that surface area of the synthesized ZIF-8 and ED-ZIF-8 was 910m2/g and 850m2/g, respectively. It was also revealed that before and after functionalization with ethylenediamine, ZIF-8 adsorbent was aminined at about 3mmol/g. In addition, the findings showed that the arsenic adsorption capacity increased from 72mg/g to 83.5mg/g. The best pH for arsenic adsorption was neutral (pH≈7). The co-existing of anions effect showed that bicarbonate, sulfate and chloride had the least inhibition effects on arsenic adsorption. This study showed that application of these class of adsorbents can be seriously addressed in solving some environmental challenges.
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•ED-ZIF-8 can be easy functionalized with amine group.•ZIF-8 functionalized with amine groups increased the adsorption capacity to arsenic (approximately 14%).•The co-existing anions had no significant effect on the fluoride removal.
Recently, there has been interest in designing recyclable and economical material for actual environmental remediation. In the present research work, amine-functionalised biosilica/alginate (NH
2
...-SiO
2
/ALG) composite was evaluated for efficient capture of carbon dioxide (CO
2
). The morphological and textural properties of NH
2
-SiO
2
/ALG composite were comprehensively characterised by BET, SEM, XRD, TGA, and FTIR techniques. The impact of influential factors on the adsorption efficiency procedure was explored in a fixed-bed reactor and the corresponding breakthrough curves were plotted. The optimum value for CO
2
removal efficiency (RE)% was predicted as 93.08% at 40°C temperature, 40 mL/min gas flow rate, and 5% moisture content. Under these conditions, the actual CO
2
RE% was achieved 92.4%. The exothermic isosteric heat of adsorption (IHA) was found as 25.3-34.8 kJ/mol representing physical interactions between NH
2
-SiO
2
/ALG and CO
2
molecules. Regeneration tests showed that the synthesised NH
2
-SiO
2
/ALG can be effectively recovered and used in multiple runs.
This paper describes the synthesis and application of novel magnetic metal-organic framework (MOF) (Fe3O4–Pyridine)/Cu3(BTC)2 for preconcentration of Pd(II) and its determination by flame atomic ...absorption spectrometry (FAAS). A Box–Behnken design was used to find the optimum conditions for the preconcentration procedure through response surface methodology. Three variables including amount of magnetic MOF, extraction time, and pH of extraction were selected as factors for adsorption step, and in desorption step, four parameters including type, volume, and concentration of eluent, and desorption time were selected in the optimization study. These values were 30mg, 6min, 6.9, K2SO4+NaOH, 6mL, 9.5 (w/v %)+0.01molL−1, 15.5min, for amount of MOF, extraction time, pH of extraction, type, volume, and concentration of the eluent, and desorption time, respectively. The preconcentration factor (PF), relative standard deviation (RSD), limit of detection (LOD), and adsorption capacity of the method were found to be 208, 2.1%, 0.37ngmL−1, and 105.1mgg−1, respectively. It was found that the magnetic MOF has more capacity compared to Fe3O4–Py. Finally, the magnetic MOF was successfully applied for rapid extraction of trace amounts of Pd (II) ions in fish, sediment, soil, and water samples.
► A novel magnetic MOF for selective extraction of Pd (II) ions has been synthesized. ► The adsorption capacity of the method was calculated to be 105.1mgg−1. ► Box–Behnken design was used to optimize the factors in adsorption and desorption steps. ► Box–Behnken design (BBD) is a fast, economical, and efficient way.
