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Herein, we report a simple and inexpensive way for the fabrication of a microelectrode, DNA modified carbon paste electrode (DNA-CPE). DNA is deposited onto carbon paste electrode surface by self-assembled monolayers. The electrochemical behaviour of DNA-CPE’s was studied by cyclic voltammetry (SWV) tests. The recorded CV’s showed two redox peacks simultaneously at E oxidation=0.3 V and E reduction=0.2 V. The recorded SWV curves at DNA-CPE have shown great efficiency in the analysis of mercury (II) at different concentrations.

A new electrode based on garlic is prepared to inhibit the effect of oxidative stress, often linked to the presence of an excess of free radicals. The electrode paste was prepared as a mixture of finely powdered of garlic together with graphite powder. The influence of variables such as the garlic loading and free radicals concentration was tested by square wave voltammetry (SWV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The obtained results were found in good correlation with garlic reputation.

The electrochemical behavior of ammonium was investigated at Ethylene Diamine Tetra-Acetic -modified carbon paste electrode (EDTA-CPE) in NaCl solution. A method was developed for the detection of the trace of this product, based on their redox reaction. The redox peaks of ammonium were observed around -0.50 V and 0.50 V (vs. SCE) in cyclic voltammetry. Experimental conditions were optimized by varying the accumulation time, EDTA loading and measuring solution pH. Calibration plots were linear under the optimized parameters over the herbicides concentration range 0.8 and 16 mmol L-1, with a detection and quantification limits about 9.38.10-7 mol L-1 and 3.21.10-6 mol L-1, respectively.

The performance of organic compounds such as, benzimidazolethiole, modified carbon paste electrode was investigated as an electrochemical sensor in the determination of lead in 0.1m phosphate buffer solution at pH 6. The organic product, 2-benzimidazole thiol, was synthesized in the laboratory to be used as modifier of the carbon paste electrode (CPE), and its complex formation with Pb (II) was studied by square wave voltammetry and cyclic voltammetry. It was found that the organic film modified electrode shows a better performance than the carbon paste electrode (CPE). Under optimal conditions, the electrode showed a good linear response to lead (II). The proposed method was applied for possible chelating agent for heavy metals.

In this paper, a novel antibiotic modified carbon paste electrode (AMX-CPE) was fabricated for the directly determination of bacteria, such Staphylococcus aureus in physiological media. Electrochemical properties and morphological study of the modified electrode were greatly studied. We report a sensitive electrochemical voltammetric method for the immediate bacteria analyzing. A Staphylococcus bacterium adsorbed on an AMX-CPE surface and provides facile electrochemical quantitative methods for electroactive bacteria. Operational parameters have been optimized, and the stripping voltammetric performance has been studied using cyclic voltammetry (CV). The peaks current intensity is highly linear, with a good sensitivity of AMX-CPE.

The aim of this work is to introduce bacteria into the matrix of natural phosphate to catalyze the phenol oxidation. The results showed that the NP-bacteria-CPE exhibited excellent electro catalytic activity to phenol. The appearance of three peaks of oxidation shows that the degradation of the phenol was total.

Bioelectrochemical systems based on polymer-bacteria thin film modified electrode were explored. The prepared polymer-bacteria modified copper electrode was characterized with voltametric methods, as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed electrode indicated a definite redox response, high conductivity and electrochemical stability. The experimental results revealed that the prepared electrode could be a feasible for degradation of hazardous phenol pollutants

The electrochemical behavior of bacteria, such Staphylococcus aureus, at clay modified carbon paste electrode is reported. The influence of variables such as the accumulation time, optical density (OD) was tested by square wave voltammetry (SWV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The interaction of bacteria and metal surface is discussed. A novel clay electrode (Arg-E) was fabricated for directly determination of bacteria in water or whole blood samples. The optical density of bacteria (OD) was determined and its evolution with the current density was plotted.

The analytical performance of developed DNA film screen printed biosensors designed for the detection of metals was evaluated. The modified surface exhibited an affinity to chelating metal ions in solution, forming complexes. Square wave voltammetry combined with a pre-concentrating process and standard additions were employed for trace analysis. Finally, cyclic voltammetry technique was used to characterize the developed DNA film surface behavior in presence of heavy metal.

We report a sensitive electrochemical voltammetric method for analyzing p-Chloroaniline using a carbon paste electrochemical (CPE) modified by porous material, such Clay (C). P-Chloroaniline strongly adsorbed on a C-CPE surface and provides facile electrochemical quantitative methods for electroactive p-Chloroaniline (p-CA). Operational parameters have been optimized, and the stripping voltammetric performance has been studied using square wave voltammetry. The peaks current intensity are highly linear, with a good sensitivity of C-CPE. These findings can lead to a widespread use of electrochemical sensors to detect chloroaniline contaminates.

A series of new benzamides were synthesized. The chemicals structures were confirmed by elemental analyses 1H NMR and 13C studies. The antioxidant activity of the synthesized compounds was evaluated by square wave voltammetry. A new approach, for antioxidant capacity determination was proposed. It is based on the using of the xanthine-xanthine oxidase system coupled with H2O2 electrochemical sensor.

The analytical performance of developed organic film screen –printed sensors designed for the detection of metals was evaluated. The modified surface exhibited an affinity to chelating metal ions in solution, forming complexes. Square wave voltammetry combined with a pre-concentrating process and standard additions were employed for trace analysis. Finally, cyclic voltammetry technique was used to characterize the developed organic film surface behavior in presence of different metals.

Three organic molecules were used as modifiers of carbon paste electrodes (CPEs) for the analysis of different metals (Pb2+, Cd2+ and Cu2+) by using Square Wave Voltammetry (SWV) technique. The effect of the modified electrodes (MO-CPEs) on the electrochemical behavior has been shown. The MO-CPEs gives the more sensitivity. The detection limits obtained in all analysis approaching 10-8 mol/L.