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Titanium/TiO2 mesoporous/reduced graphene oxide structure for construction of a hybrid electrode was successfully developed using a facile and effective spin-coating technique. The as-prepared structures were characterized using ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, RAMAN analysis, scanning electron microscopy (SEM) coupled with elemental analysis (EDX), and atomic force microscopy (AFM). In addition, the electrochemical behavior was assessed by cyclic voltammetry (CV) in a 1M KNO3 supporting electrolyte and in the presence of 4 mM K3Fe(CN)6 to determine the electroactive surface area and apparent diffusion coefficient of the hybrid electrode. The charge transfer resistance was investigated via electrochemical impedance spectroscopy (EIS) in a 0.1 M Na2SO4 supporting electrolyte to confirm the role of reduced graphene oxide on the electrode's surface. The potential application of as-obtained hybrid electrodes in electroanalysis was tested through cyclic voltammetry in the presence of doxorubicin as the target analyte, in the concentration range between 1 to 7 mg L−1 DOX. By using mesoporous TiO2 with a high specific surface area (~140 m2 g−1) in the synthesis of the composite material based on a Ti/TiO2(Ms)/rGO hybrid structure, was obtained a 2.3-times increase in electroactive surface area than the geometrical surface area of the hybrid electrode. These results provide new insights into the development of high-performance and cost-effective electrochemical sensors based on reduced graphene oxide films on metallic structures for applications in the detection processes of drugs from wastewater. [ABSTRACT FROM AUTHOR]

Background: The extracts of Allium cepa are known for their medical use: antioxidant, antiinflammatory, antimicrobial, fibrinolytic and antiplatelet properties. Our study aims to establish, using in vitro tests, the antiplatelet and antioxidant character, the link between them and the extract acidity, from seven varieties of A. cepa. Methodology: The qualitative and quantitative presence of polyphenols and anthocyanins in the extracts was determined using UV-Vis and HPLC. Quantitative determination of the thiosulfinates compounds was calculated using their reaction with 4-mercaptopyridine. Antioxidant character was determined using 3 methods (FC, DPPH and TEAC), and antiplatelet effect was measured by in vitro tests on platelet rich plasma obtained from human blood. Principal Findings/Results: The white variety of A. cepa has the most alkaline pH, the largest amount of thiosulfinate compounds and the most powerful antiplatelet effect, but a very small amount of flavonoids and an antioxidant effect almost nonexistent, in contrast with red variety of A. cepa which is the opposite. Conclusions/Significance: The white variety of A. cepa had very high anitiplatelet activity suggesting the potential use of A. cepa extract in treating cardiovascular diseases.

Pharmaceuticals contaminants in waters exhibit a significant threat on the human health and the ecosystem quality. This research demonstrates the utility of a silver-doped zeolite-modified carbon nanofiber-epoxy (AgZ-CNF) prepared by two-roll mill method in development of the fast methodology for the detection of fluoxetine (FXT) in the aqueous solution. The results showed the role of zeolite that improved the sensitivity and the limit of detection of FXT resulted to the possibility to propose a specific preconcentration-based detection protocol. The silver contributed to decreasing the anodic over potential for FXT oxidation and hence, for FXT detection. The best sensitivity of 2.007 µA µM-1 and lowest limit of detection of 19 nM are were obtained for preconcentration-cyclic voltammetry based scheme, which is very promising for the detection of FXT at trace levels. Also, the chronoamperometry operated at 0.350 V/SCE specific to silver involving and +1.1V/SCE characteristics to the carbon nanofiber, allowed FXT detection in the aqueous solution. The long life time and the stable response for FXT detection was found for AgZCNF composite electrode, which suggests its practical utility in FXT determination in the real water sources. [ABSTRACT FROM AUTHOR]

Arsenic removal from groundwater as drinking water source was investigated using electrocoagulation (EC) process with horizontal anodes of iron plate under galvanostatic regime. The current density of 5 A⋅m-2 was determined as the optimum operating conditions at the electrolysis time of maximum 25 minutes and pH ranged between 6.5 to 8.5, by which the arsenic concentration was reduced below 10 µg⋅L-1. The aspects related to the arsenic removal mechanism were discussed by Zeta potential. This iron anode-based EC process was successfully applied for the removal of arsenic from a real groundwater characterized by high arsenic concentration of 255.80 µg⋅L-1 under aeration conditions. After 15 minutes of electrolysis the arsenic removal efficiency of 99.59% was achieved under the optimum operating conditions with the energy consumption of 0.006 kWh⋅m-3 that is 100 times lower than the reported in the literature. [ABSTRACT FROM AUTHOR]