Sharif Digital Repository

In this work, uniform and monodisperse hollow carbon spheres (HCSs) are synthesized through two different processes using polydopamine (PDA), as a carbon precursor, and silica core as a template, under the modified Stöber condition. The surface morphology of the synthesized structures is characterized by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier-transform infrared spectroscopy (FT-IR). In the next step, the electrochemical behavior of isoprenaline (ISPN) is investigated by using glassy carbon electrode modified with a thin film of the synthesized hollow carbon spheres. The electrochemical characterization of the modified electrodes is... 

A novel electrochemical sensor for clonazepam (CLNP) was fabricated based on immobilizing cellulose nanofibers/carbon nanoparticles (CNFs/CNPs) nanocomposite on glassy carbon electrode (CNFs/CNPs/GCE). The combination of CNFs and CNPs produced a novel kind of structurally uniform and electro-analytically active nanocomposite. The surface morphology of CNFs/CNPs layer deposited onto glassy carbon electrode was characterized by scanning electron microscopy. The results of the voltammetric investigations showed a considerable enhancement in the cathodic peak current of CLNP (up to 60 times) on the surface of CNFs/CNPs/GCE relative to the bare GCE. Under the optimal conditions, the modified... 

The catalytic activity of Pt/Ni/TiO 2 nanotubes electrode toward glucose has been studied. Fabrication of Pt/Ni nanostructures was done in a single-bath solution through electrochemical pulse method by changing the deposition potential between -0.3 and -4 V vs. SCE, respectively. The resulting modified electrode represented high conductivity due to the effective presence of metallic components and uniform surface area caused by dispersion of Pt and Ni nanostructures. The scanning electron microscopy images also confirmed that a large amount of metals colonies were well-dispersed at the edge of the TiO 2 nanotubes. In addition, the Pt/Ni TiO 2 nanotubes modified electrode exhibited an... 

As a selective estrogen receptor modulator, raloxifene (RXF) prevent of osteoporosis in postmenopausal women by estrogenic actions on bone and decreases the risk of invasive breast cancer by anti-estrogenic actions on the breast and uterus tissue. However, RXF may increase the risk of blood clots, including deep vein thrombosis and pulmonary embolism. For the first time glassy carbon electrode modified with a thin film of melamine/carbon nanoparticles (CNPs/Mela) was constructed and used for the sensitive voltammetric determination of RXF. In comparison with unmodified electrode, the presence of the CNPs/Mela film resulted in a remarkable increase in the peak currents and sharpness of the... 

The emergence of nanoscience and nanotechnology has opened up new horizons to researchers. In this regard, carbon nanomaterials are considered as the cornerstone of numerous investigations. Among various carbon nanostructures, “Carbon nanoparticles (CNPs)” have attracted a great deal of attention during the past few years due to their unique properties such as high surface area, non-toxicity, biocompatibility as well as simple and low-cost synthetic procedures via environmentally friendly routes. Thanks to these properties along with their interesting optical behavior, CNPs have found diverse applications in the fields of bioimaging, nanomedicine, photo/electro-catalysis, and bio/chemical... 

A novel modified electrode is reported for the electrochemical investigation of the oxidation mechanism and also voltammetric determination of raloxifene (RLX). The surface of the electrode was modified with a thin layer of reduced graphene oxide-carbon nanotube nano-composite (rGO-CNT) was prepared, and successfully employed for the electrochemical studies of RLX. The morphology of the sensor surface was characterized by using a scanning electron microscopy. RLX Oxidation response significantly increased at the GCE covered with rGO-CNT, regarding the bare and CNT or rGO functionalized GCE. Experimental parameters affecting the RLX response were optimized and mechanism of the RLX oxidation... 

The electrochemical behavior of captopril at the surface of a carbon-paste electrode (CPE) modified with cobalt-5-nitrolsalophen (CoNSal) is described. The prepared electrode shows an excellent electrocatalytic activity toward the oxidation of captopril, which is leading to marked lowering in the anodic overpotential and considerable improvement of sensitivity (anodic current). Whereas at the surface of unmodified electrode an electrochemical activity for captopril cannot be observed, a very sharp anodic wave with an anodic peak potential about 650 mV (versus Ag/AgCl) is obtained using the prepared modified electrode. This catalytic wave is assigned to mediating of Co(III)/Co(II) redox... 

Nickel modified graphite electrodes (G/Ni) prepared by galvanostatic deposition were examined for their redox process and electrocatalytic activities towards the oxidation of methanol, ethanol, 1-propanol and 2-propanol in alkaline solutions. The methods of cyclic voltammetry (CV), chronoamperometry (CA) and impedance spectroscopy (EIS) were employed. In CV studies, the electrochemical response, peak current varied in the order of MeOH > EtOH > 1-PrOH > 2-PrOH. Under the CA regime, a higher catalytic rate constant obtained for methanol oxidation was in agreement with CV measurements. Lower charge transfer resistance was obtained for low carbon alcohols oxidation and significantly higher...