An electrochemical sensor for rizatriptan benzoate determination using Fe3O4 nanoparticle/multiwall carbon nanotube-modified glassy carbon electrode in real samples.

In this paper a sensitive and selective electrochemical sensor for determination of rizatriptan benzoate (RZB) was proposed. A glassy carbon electrode was modified with nanocomposite of multiwalled carbon nanotubes (MWCNTs) and Fe3O4 nanoparticles (Fe3O4/MWCNTs/GCE). The results obtained clearly show that the combination of MWCNTs and Fe3O4 nanoparticles definitely improves the sensitivity of modified electrode to RZB determination. The morphology and electroanalytical performance of the fabricated sensor were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), square wave voltammetry (SWV) and cyclic voltammetry (CV). Also, the effect of experimental and instrumental parameters on the sensor response was evaluated. The square wave voltammetric response of the electrode to RZB was linear in the range 0.5-100.0 μmol L(-1) with a detection limit of 0.09 μmol L(-1) under the optimum conditions. The investigated method showed good stability, reproducibility and repeatability. The proposed sensor was successfully applied for real life samples of blood serum and RZB determination in pharmaceutical.

Madrakian T ，Maleki S ，Heidari M ，Afkhami A ... -  《-》

Facile stripping voltammetric determination of haloperidol using a high performance magnetite/carbon nanotube paste electrode in pharmaceutical and biological samples.

Multi-walled carbon nanotubes decorated with Fe3O4 nanoparticles were prepared to construct a novel sensor for the determination of haloperidol (Hp) by voltammetric methods. The morphology and properties of electrode surface were characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy. This modified sensor was used as a selective electrochemical sensor for the determination of trace amounts of Hp. The peak currents of differential pulse and square wave voltammograms of Hp increased linearly with its concentration in the ranges of 1.2×10(-3)-0.52 and 6.5×10(-4)-0.52μmol L(-1), respectively. The detection limits for Hp were 7.02×10(-4) and 1.33×10(-4)μmol L(-1) for differential pulse and square wave voltammetric methods, respectively. The results show that the combination of multi-walled carbon nanotubes and Fe3O4 nanoparticles causes a dramatic enhancement in the sensitivity of Hp quantification. This sensor was successfully applied to determine Hp in pharmaceutical samples and biological fluids. The fabricated electrode showed excellent reproducibility, repeatability and stability.

Bagheri H ，Afkhami A ，Panahi Y ，Khoshsafar H ，Shirzadmehr A ... -  《-》

Adsorptive anodic stripping differential pulse voltammetric determination of CellCept at Fe(3)O(4) nanoparticles decorated multi-walled carbon nanotubes modified glassy carbon electrode.

A simple and sensitive method based on adsorptive anodic stripping differential pulse voltammetry (AASDPV) for the determination of cellcept, using a magnetic Fe3O4 nanoparticles and functionalized (carboxylated) multi-walled carbon nanotubes modified glassy carbon electrode (f-MWCNs/Fe3O4/GCE) was developed. In phosphate buffer solution (pH = 5), the voltammogram of cellcept exhibited tow anodic peaks and the well-defined peak at about 0.611 V vs SCE was used for its monitoring. The modified electrode was characterized by different methods such as electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and cyclic voltammetry (CV). The experimental parameters, such as pH, deposition potential and time, as well as scan rate were optimized. Under the optimized conditions, Ip (μA) was proportional to the cellcept concentration in the range of 0.05-200 μM (R2 = 0.9989) with a detection limit of 9.0 nM and limit of quantification of 30.2 nM. The recovery was >98%. The practical analytical utilities of the modified electrode were demonstrated by the determination of cellcept in human urine and blood serum samples. Modified electrode showed an adequate sensitivity and stability for evaluated samples.

Gholivand MB ，Solgi M 《-》

Amperometric sensing of anti-HIV drug zidovudine on Ag nanofilm-multiwalled carbon nanotubes modified glassy carbon electrode.

The zidovudine (ZDV) is the first drug approved for the treatment of HIV virus infection. The detection and determination of this drug are very importance in human serum because of its undesirable effects. A new ZDV sensor was fabricated on the basis of nanocomposite of silver nanofilm (Ag-NF) and multiwalled carbon nanotubes (MWCNTs) immobilized on glassy carbon electrode (GCE). The modified electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), cyclic voltammetry (CV), and linear sweep voltammetry (LSV) techniques. Results showed that the electrodeposited silver has a nanofilm structure and further electrochemical studies showed that the prepared nanocomposite has high electrocatalytic activity and is appropriate for using in sensors. The amperometric technique under optimal conditions is used for the determination of ZDV ranging from 0.1 to 400ppm (0.37μM-1.5mM) with a low detection limit of 0.04ppm (0.15μM) (S/N=3) and good sensitivity. The prepared sensor possessed accurate and rapid response to ZDV and shows an average recovery of 98.6% in real samples.

Rafati AA ，Afraz A 《-》

Simultaneous voltammetric determination of cadmium(II), lead(II), mercury(II), zinc(II), and copper(II) using a glassy carbon electrode modified with magnetite (Fe(3)O(4)) nanoparticles and fluorinated multiwalled carbon nanotubes.

Wu W ，Jia M ，Wang Z ，Zhang W ，Zhang Q ，Liu G ，Zhang Z ，Li P ... -  《-》