Biomedical subjects

Norouz Maleki

Publications and source records attributed to Norouz Maleki.

3 recordsLinked to original sources

PubMed2006

Highly stable electrochemical oxidation of phenolic compounds at carbon ionic liquid electrode.

A carbon ionic liquid electrode (CILE) was used for the investigation of the electrochemical oxidation of phenolic compounds in acidic media using cyclic voltammetry, chronoamperometry and square wave voltammetry techniques. The results indicate that, contrary to many other electrodes, the oxidation of phenolic compounds on CILE is highly stable and does not result in electrode fouling. Cyclic voltammetry showed that phenolic compounds such as phenol, 2,4-dichlorophenol and catechol were oxidized at CILE and remained electroactive after multiple cycles and at high concentrations of phenol. The cyclic voltammetric response of the CILE is very stable with more than 99% of the initial activity remaining after 20 s of stirring of a 0.5 mM solution of phenol.

Carbon↗

PubMed2006

Simultaneous determination of dopamine, ascorbic acid, and uric acid using carbon ionic liquid electrode.

A recently constructed carbon composite electrode using room temperature ionic liquid as pasting binder was employed as a novel electrode for sensitive, simultaneous determination of dopamine (DA), ascorbic acid (AA), and uric acid (UA). The apparent reversibility and kinetics of the electrochemical reaction for DA, AA, and UA found were improved significantly compared to those obtained using a conventional carbon paste electrode. The results show that carbon ionic liquid electrode (CILE) reduces the overpotential of DA, AA, and UA oxidation, without showing any fouling effect due to the deposition of their oxidized products. In the case of DA, the oxidation and reduction peak potentials appear at 210 and 135mV (vs Ag/AgCl, KCl, 3.0M), respectively, and the CILE shows a significantly better reversibility for dopamine. The oxidation peak due to the oxidation of AA occurs at about 60mV. For UA, a sharp oxidation peak at 340mV and a small reduction peak at 250mV are obtained at CILE. Differential pulse voltammetry was used for the simultaneous determination of ternary mixtures of DA, AA, and UA. Relative standard deviation for DA, AA, and UA determinations were less than 3.0% and DA, AA, and UA can be determined in the ranges of 2.0x10(-6)-1.5x10(-3), 5.0x10(-5)-7.4x10(-3), and 2.0x10(-6)-2.2x10(-4)M, respectively. The method was applied to the determination of DA, AA, and UA in human blood serum and urine samples.

Ascorbic Acid↗

PubMed2006

High-performance carbon composite electrode based on an ionic liquid as a binder.

Ionic liquid, n-octylpyridinum hexafluorophosphate (OPFP) has been used to fabricate a new carbon composite electrode with very attractive electrochemical behavior. This type of carbon electrode has been constructed using graphite mixed with OPFP as the binder. The electrode has combined advantages of edge plane characteristics of carbon nanotubes and edge plane pyrolytic graphite electrodes together with the low cost of carbon paste electrodes and robustness of metallic electrodes. It provides a remarkable increase in the rate of electron transfer of different organic and inorganic electroactive compounds and offers a marked decrease in the overvoltage for biomolecules such as NADH, dopamine, and ascorbic acid. It also circumvents NADH surface fouling effects as well as furnishing higher current density for a wide range of compounds tested. Depending on the choice of the electrolyte, the electrode can have the ion-exchange property and adsorptive characteristics of clay-modified electrodes. The proposed electrode thus allows sensitive, low-potential, simple, low-cost, and stable electrochemical sensing of biomolecules and other electroactive compounds. Scanning electron microscopy images indicate significant improvement in the microstructure of the proposed electrode compared to carbon paste electrodes. Such abilities promote new opportunities for a wide range of electrochemical and biosensing applications.

Journal Article↗