In this work, a low cost glucose and methanol nonenzymatic sensor was prepared using nickel oxide (NiO) nanofilm electrodeposited on a bare Cu electrode. Electrochemical deposition was assisted with cetyl trimethylammonium bromide (CTAB) as a template. Scanning electron microscopy (SEM) was applied to observe the surface morphology of the modified electrode. Cyclic voltammetry (CV) and amperometry techniques were used to study the electrocatalytic behavior of NiO porous film in glucose and methanol detection. For glucose sensing, the electrode showed a linear relationship in the concentration range of 0.01-2.14 mM with a low limit of detection (LOD) 1.7 µM (signal/noise ratio (S/N)=3). Moreover, high sensitivities of 4.02 mA mM?1 cm?2 and 0.38 mA mM?1 cm?2 respectively in glucose and methanol monitoring suggested the modified electrode as an excellent sensor. The NiO-Cu modified electrode was relatively insensitive to common biological interferers. This sensor possessed good poison resistance towards chloride ions, and long term stability and significant selectivity towards glucose and methanol. Finally the proposed sensor was successfully applied for determination of glucose in human blood serum samples.
The bulk room-temperature polymerization of styrene initiated by environmentally friendly catalysts Maghnite-Na+ is investigated. The catalyst removed from the reaction mixture simply by filtration could be regenerated and reused. The effect of the Maghnite-Na+ catalyst loading on degree of polymerization had been studied and state their inverse relation. The catalyst was characterized by X-ray diffraction and FTIR spectroscopy.
The current development of polyurethane self-healing materials has been evaluated and reviewed. Three main ways of self-healing – microcontainers, microvascular networks and reversible polymers - are described, and recent most prominent examples of self-healing materials applications presented.
The adsorption behavior of a potential polynuclear Schiff base, (s)-2-(anthracen-9(10H)-ylideneamino)-3-phenyl propanoic acid (A9Y3PPA) on carbon steel (CS) in 1M hydrochloric acid solution has been investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies. The surface morphology of the carbon steel specimens in the presence and absence of the inhibitor was evaluated by AFM analysis. The corrosion inhibition efficiencies of parent amine and parent ketone on carbon steel in 1M HCl solution have also been investigated using weight loss studies. The adsorption of A9Y3PPA obeys Langmuir adsorption isotherm. Thermodynamic parameters (Kads, ∆G0ads) were calculated using the adsorption isotherm. Activation parameters of the corrosion process (Ea, ∆H* and ∆S*) were also calculated from the corrosion rates obtained from temperature studies. Tafel plot analysis revealed that A9Y3PPA acts as a mixed type inhibitor. A probable inhibition mechanism was also proposed.
Enzymatic assay, based on oxidation-reduction reaction catalyzed by alcohol dehydrogenase, is one of the methods used to determine ethanol concentration. The present study was directed to determine the exact amount of enzyme required to accomplish oxidation-reduction reaction so that the concentration of ethanol in the sample can be determined precisely and accurately. Results of the present study indicate that the lowest unit activity of the enzyme that can be used for ethanol determination is 4000 units/mL, even though longer incubation time compared to the original method was used to ensure reaction completion. Validation of the method confirmed that the assay have acceptable linearity range within 0.01 - 0.06% (v/v) of ethanol with correlation coefficient of 0.9999. Both accuracy and precision parameters fulfill the Association of Analytical Communities (AOAC) International requirement, and therefore can be accepted as a quantitative analysis method. Limit of detection and limit of quantitation for the modified method were 0.0017% (v/v) and 0.0056% (v/v), respectively.