Nitrogen (N)-doped carbon and its non-noble metal composite replacing platinum-based oxygen reduction reaction (ORR) electrocatalysts still have some fundamental problems that remain. Here the micron-sized commercial polyacrylonitrile-based carbon fiber (PAN-CF) electrode was modified using an electrochemical method, converting its inherent pyridinic-N into 2-pyridone (or 2-hydroxyl pyridine) f...

In the present paper, the use of a novel carbon paste electrode modified by 7,8-dihydroxy-3,3,6-trimethyl-3,4-dihydrodibenzo[b,d]furan-1(2H)-one (DTD) and oxidized multi-walled carbon nanotubes (OCNTs) is described for determination of levodopa (LD), acetaminophen (AC) and tryptophan (Trp) by a simple and rapid method. At first, the electrochemical behavior of DTD is studied, then, the mediated...

Direct electron transfer of hemoglobin (Hb) was realized by immobilizing Hb on a carboxyl functionalized multi-walled carbon nanotubes (FMWCNTs) and gold nanoparticles (AuNPs) nanocomplex-modified glassy carbon electrode. The ultraviolet-visible absorption spectrometry (UV-Vis), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) methods were utilized for additional cha...

This work aims to clarify the nano-structural transformation accompanying the loss of activity and selectivity for H2O2 synthesis of Pd and AuPd nanoparticles supported on N-functionalized carbon nanotubes (NCNTs). High resolution XPS allowed discriminating metallic Pd, electronically-modified metallic Pd hosting impurities and cationic Pd. This is paralleled by morphological heterogeneity obse...

In the present paper, electrochemical methods were used to investigate the behavior of ascorbic acid at a carbon paste electrode modified with 2,2'-((1E)-(1,2 phenylenebis(azanylylidene)) bis(methanylylidene))bis(benzene-1,4-diol) (PBD) and oxidized multiwall carbon nanotubes. The modified carbon paste electrode showed high electrocatalytic activity toward ascorbic acid; the current was enhance...

Multi-walled carbon nanotubes (MWCNTs) were immobilized on the surface of a glassy carbon electrode (GCE) in the presence of cetyltrimethylammonium bromide (CTAB) to form a MWCNTs-CTAB nanocomposite-modified electrode. The electrocatalytic response of the modified electrode towards tryptophan (Trp) was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The surface...

Oxygen reduction kinetics on bare and Pt-modified Ru(10/1̄/0) and Ru(0001) single crystal surfaces, and on carbon-supported Ru nanoparticles have been investigated. Spontaneous deposition of Pt was used to form approximately 1.5 and 0.5 monolayers on Ru single crystals and nanoparticles, respectively. The reaction kinetics of O2 on single crystal surfaces has a small structural dependence. It is...

background: stevia rebaudiana bertoni, an important anti-diabetic medicinal plant, becomes an inevitable alternative to sugar. due to the propagation difficulties, tissue culture is the best alternative for rapid mass propagation of stevia plants. objective: the present study was conducted to optimize a protocol for rapid micropropagation of stevia rebaudiana by shoot tip explants and to invest...