Preparation and characterization of Rutin loaded on magnetic graphene quantum dot nano career with metals (Ag, Zn, Mg, Co, and Fe) and study of antioxidant and electrochemical properties.

Rutin, is one of the flavonoids, and has high antioxidant properties, but is limited due to low solubility in aqueous solutions. To increase the antioxidant performance and permeability, the synthesis of magnetic graphene quantum dot metal nanocomposites and the antioxidant activity of the prepared nanocomposites have been studied. Rutin was treated with metal magnetic nanocomposites, GQD-MFe2O4, that included metals like Silver, Magnesium, Zinc, Cobalt, and Iron. The metal nanocomposites reacted with Rutin to obtain Rutin-bearing magnetic nanocomposites. The GQD-MFe2O4 nanocomposites were synthesized by common hydrothermal pyrolysis of citric acid and subsequent the addition of iron nitrate and metal nitrate (M= Ag, Mg, Co, Zn, Fe) to the media. The scavenging test of free radical activity and DPPH test of prepared nanomagnetic composites show good antioxidant activity. The results show that the derivatives of magnetic nanocomposites have different antioxidant activities compared to Rutin as ordered: GQD-ZnFe2O4-Ru

Synthesis and characterization of amino sulfonic acid functionalized graphene oxide as a potential carrier for quercetin.

In this investigation, a new nanocomposite as a nanocarrier based on functionalized graphene oxide was synthesized by reaction of tetraethylenepentamine and chlorosulfonic acid with functional groups on the surface of GO. The synthesized nanocomposite was characterized by FT-IR, XRD TGA, FE-SEM, EDAX, TEM, and AFM analysis. To explore the potential of nanocomposites in drug delivery, the loading and releases of quercetin as an anticancer drug were investigated. The result displayed that more than 90% of the drug was loaded on the nanocarrier and the release of the drug is depending on the pH of the environment such that the releases of the drug in Gastric and intestinal conditions were up to 50% and 30%, respectively. The analysis of toxicity effect on the normal and cancer cells indicated that the nanocarrier with the drug has potential for cancer cells therapy without cytotoxic effect on normal cells in IC50 concentration.

A highly selective green supported liquid membrane by using a hydrophobic deep eutectic solvent for carrier-less transport of silver ions.

A new supported liquid membrane (SLM) was designed by using a suitable deep eutectic solvent (DES) as the hydrophobic liquid membrane phase for the selective and facilitated carrier-less transport of Ag+ ions. The deep eutectic solvent was composed of a 4/1 molar ratio of l-menthol/salicylic acid and was impregnated into a microporous polypropylene membrane to prepare a novel carrier-less SLM system. The highly selective facilitated transport of silver ions was accomplished by using sodium thiosulfate as a highly selective stripping agent for Ag+ ions in the aqueous strip phase (SP). Some important factors, including the concentration of picric acid in the feed phase (FP), pH of the two aqueous phases, stirring rate, transport time, and nature and concentration of the stripping agent were also investigated and optimized. In the presence of 2.8 × 10-2 mol L-1 picrate ions as an appropriate ion pairing agent in the FP and 0.025 mol L-1 thiosulfate as a convenient metal ion acceptor in the SP, the amount of Ag+ ion transport found to occur almost quantitatively after 60 min is 90%. Compared with other SLM systems reported in the literature, the designed DES-SLM system exhibited suitable permeability and higher selectivity for Ag+ ion transport from aqueous solutions containing Fe2+, Mn2+, Cu2+, Ni2+, Pb2+, and Cd2+ as competing metal ions.

Immobilization of trypsin onto Fe3O4@SiO2 -NH2 and study of its activity and stability.

The preparation of biocatalysts based on immobilized trypsin is of great importance for proteomic research, industrial applications and organic synthesis. Here in, we have developed a facile method to immobilize trypsin on magnetic nanoparticles. Fe3O4 nanoparticles were synthesized by co-precipitating Fe2+and Fe3+in an ammonia solution and then coated by silicon dioxides were developed by sol-gel method. The silica-coated Fe3O4 nanoparticles were further modified with 3-aminopropyltriethoxysilane, resulting in attaching of primary amine groups on the surface of the particles. Trypsin from porcine pancrease was then immobilized on the magnetic core-shell particles by using glutaraldehyde as a cross-linker. The synthesis steps and characterizations of immobilized trypsin were examined by FT-IR, XRD, TGA, EDX and SEM. The results showed that the enzyme immobilization increased the enzyme activity in different pHs and temperatures, without any changes in the optimum pH and temperature for enzyme activity. The Kinetic results showed that the enzyme immobilization decreased and increased Vmax and Km values, respectively. The stability results showed that the enzyme immobilization improved trypsin thermostability in the absence and presence of 10% (v/v) of the used solvents (DMF, THF, DMSO, ACN and 1, 4-Dioxane). The reusability results indicated that the immobilized enzyme maintained 85% of its activity after 6 periods of activity.

1,1'-Bis(tert-butyl-dimethyl-sil-yl)ferrocene.

The asymmetric unit of the title compound, [Fe(C11H19Si)2], consists of one half of a ferrocene derivative. The Fe(II) atom lies on a twofold rotation axis, giving an eclipsed conformation for the cyclo-penta-dienyl ligands. No significant inter-molecular inter-actions are observed in the crystal structure.

A Fast Response Membrane Sensor based on Ethyl 1, 2, 3, 4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate for Detection of Lanthanum (III) Ions at Wide Concentration Range.

A PVC membrane La (III) ion-selective electrode has been constructed using ethyl1,2,3,4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate (ETMPTC) as a neutral ionophore. This electrode responds to La (III) ion with a sensitivity of 19.9 ± 0.3 mV/decade over the range 9.3 × 10-8 to 1.0 × 10-1 M at pH 3.0-10.0. The limit of detection was 1.7 × 10-8 M. It has a response time of < 11s and can be used for at least 3 months without any divergence in potentials. The proposed electrode shows fairly good discrimination of La (III) ion from several cations. The effect of organic solvents on electrode response was examined. The results show that this electrode can be used in ethanol media until 20% (v/v) concentration without interference. The isothermal temperature coefficient of this electrode amounted to 0.00013 V/ °C. This sensor not only was used as an indicator electrode in potentiometric titration of lanthanum ion against EDTA but also was used to determination of La3+ concentration in the presence of certain interfering ions.