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1 – 10 of 57Nur Shahira Abdul Nasir, Revathy Deivasigamani, Muhammad Khairulanwar Abdul Rahim, Siti Nur Ashakirin Mohd Nashruddin, Azrul Azlan Hamzah, M. Farhanulhakim M. Razip Wee and Muhamad Ramdzan Buyong
The purpose of this paper is to visualize protein manipulation using dielectrophoresis (DEP) as a substantial perspective on being an effective protein analysis and biosensor…
Abstract
Purpose
The purpose of this paper is to visualize protein manipulation using dielectrophoresis (DEP) as a substantial perspective on being an effective protein analysis and biosensor method as DEP is able to be used as a means for manipulation, fractionation, pre-concentration and separation. This research aims to quantify DEP using an electrochemical technique known as cyclic voltammetry (CV), as albumin is non-visible without any fluorescent probe or dye.
Design/methodology/approach
The principles of DEP were generated by an electric field on tapered DEP microelectrodes. The principle of CV was analysed using different concentrations of albumin on a screen-printed carbon electrode. Using preliminary data from both DEP and CV methods as a future prospect for the integration of both techniques to do electrical quantification of DEP forces.
Findings
The size of the albumin is known to be 0.027 µm. Engineered polystyrene particle of size 0.05 µm was selected to mimic the DEP actuation of albumin. Positive DEP of the sample engineered polystyrene particle was able to be visualized clearly at 10 MHz supplied with 20 Vpp. However, negative DEP was not able to be visualized because of the limitation of the apparatus. However, albumin was not able to be visualized under the fluorescent microscope because of its translucent properties. Thus, a method of electrical quantification known as the CV technique is used. The detection of bovine serum albumin (BSA) using the CV method is successful. As the concentration of BSA increases, the peak current obtained from the voltammogram decreases. The peak current can be an indicator of DEP response as it correlates to the adsorption of the protein onto the electrodes. The importance of the results from both CV and DEP shows that the integration of both techniques is possible.
Originality/value
The integration of both methods could give rise to a new technique with precision to be implemented into the dialyzers used in renal haemodialysis treatment for manipulation and sensing of protein albumin.
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Ibrahym Ahmad, Anasyida Abu Seman and Ahmad Azmin Mohamad
The purpose of this paper is to study the mechanism of electrochemical dissolution of SAC305 solder in mild acid solution.
Abstract
Purpose
The purpose of this paper is to study the mechanism of electrochemical dissolution of SAC305 solder in mild acid solution.
Design/methodology/approach
Cyclic voltammetry (CV) was used to obtain electrochemical dissolution peaks followed by chronoamperometery (CA) to investigate the dissolution mechanism at each peak. Structural and microstructural characterization was performed to verify the CA analysis. Potentiodynamic polarization was performed afterwards to determine the corrosion potential of every phase in SAC305.
Findings
The early cycle of CV exhibits only dissolution peaks of β-Sn until intermetallic compound (IMC) peaks emerged at a later cycle. CA performed for 24 h at selected potentials reveals that β-Sn can be removed completely from the sample without disrupting the IMC network at a suitable potential. This was later verified by XRD and SEM. Potentiodynamic polarization determined the corrosion potential of IMC as −0.36 V.
Originality/value
The mechanism of anodic dissolution of SAC305 was studied and proposed.
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Elbahi Djaalab, Mohamed Elhadi Samar, Saida Zougar and Rochdi Kherrat
A new electrochemical analysis based on ß-cyclodextrin (ß-CD) was developed for penicillin V (Peni-V) using polyaniline as a conducting polymer.
Abstract
Purpose
A new electrochemical analysis based on ß-cyclodextrin (ß-CD) was developed for penicillin V (Peni-V) using polyaniline as a conducting polymer.
Design/methodology/approach
The preparation of modified electrode involves the incorporation of β-CD with membrane of polyaniline. Polyaniline, incorporating β-CD, was prepared by electrochemical polymerization method in a medium of hypochloride. Cyclic voltammetry and electrochemical impedance have been used to characterize this sensor. The detection and the kinetic study of modified platinum electrode are evaluated.
Findings
Results clearly indicate that β-CDs interfere with the polymerization mechanism with an inhibition factor. The inclusion phenomenon of β-CDs has been studied and applied to detect Peni-V. The principle of this electrochemical sensor is based on the chemical properties of β-CD, which were studied using the cyclic voltammetric method and impedance spectroscopy. The electrochemical behavior of Peni-V at concentrations between 10–8 and 10–2 M was measured versus Ag/AgCl at pH 7.4 and 30°C in a phosphate alkaline buffer. Relationship of Peni-V concentration in logarithmic mathematical form with current in potentiometric method and with resistance in impedimetric method were obtained.
Originality/value
The present study showed that the Pt electrode modified with Polyaniline–β-CD was an excellent candidate for sensitive penicillin analysis. The proposed electroanalytical technique is rapid, simple and inexpensive.
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Kisan Koirala, Jose H. Santos, Ai Ling Tan, Mohammad A. Ali and Aminul H. Mirza
This paper aims to develop an inexpensive, portable, sensitive and environmentally friendly electrochemical sensor to quantify trace metals.
Abstract
Purpose
This paper aims to develop an inexpensive, portable, sensitive and environmentally friendly electrochemical sensor to quantify trace metals.
Design/methodology/approach
A sensor was constructed by modifying carbon paste electrode for the determination of lead, cadmium and zinc ions using square wave anodic stripping voltammetry (SWASV). The modified electrode was prepared by inserting homogeneous mixture of 2-hydroxy-acetophenonethiosemicarbazone, graphite powder and mineral oil. Various important parameters controlling the performance of the sensor were investigated and optimized. Electrochemical behavior of modified electrode was characterized by cyclic voltammetry.
Findings
Modified carbon pastes electrodes showed three distinct peaks at −0.50, −0.76 and −1.02 V vs silver/silver chloride corresponding to the oxidation of lead, cadmium and zinc ions at the electrode surface, respectively. The highest peak currents for all the metal ions under study were observed in the phosphate buffer solution at pH 1 with a deposition time of 70 s. The sensor exhibited linear behavior in the range of 0.25-12.5 μg mL-1 for lead and cadmium and 0.25-10.0 μg mL−1 for zinc. The limit of detection was calculated as 78.81, 96.17 and 91.88 ng mL−1 for Pb2+, Cd2+and Zn2+, respectively. The modified electrode exhibited good stability and repeatability.
Originality/value
A chemically modified electrode with Schiff base was applied to determine the content of cadmium, lead and zinc ions in aqueous solutions using SWASV.
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F.N. Grosser and R.S. Gonçalves
This paper describes new experimental evidence of the electropolymerization of furfural on non‐noble metals such as low‐carbon steel. The organic compound (2‐furancarboxaldehyde…
Abstract
Purpose
This paper describes new experimental evidence of the electropolymerization of furfural on non‐noble metals such as low‐carbon steel. The organic compound (2‐furancarboxaldehyde) was selected because it is easily obtained from biomass and other sources. These results confirm the possibility of synthesizing a polymeric film, with good adherence and stability that provides a new protective barrier against corrosion to this kind of metal.
Design/methodology/approach
Electrochemical methods such as chronoamperometry, chronopotentiometry and cyclic voltammetry (CV) were used to synthesize and characterize the polymer formed on the electrode surface. Some electrochemical impedance experiments were conducted in order to confirm the electrochemical behavior modification of the electrode, due to the presence of the organic film on the surface.
Findings
The polymer film could be grown galvanostatically, potentiostatically or, during CV. The corrosion protection afforded by polyfurfural (PFy) that had been formed on a low‐carbon steel surface was confirmed by the CV, EIS and polarization curves.
Research limitations/implications
The possible synthesis of a new polymeric structure on a non‐noble metal is interesting from a practical point of view. However, more experiments are necessary in order to test other organic solvents and other non‐noble metals such as zinc, aluminium, copper, etc.
Practical implications
The corrosion protection afforded by PFy that had been formed on a low‐carbon steel surface was confirmed by the CV, EIS and polarization curves. Anodic current values associated with metal oxidation decreased when the metal surface was covered with the organic film.
Originality/value
This is the first paper that deals with the electropolymerization of furfural on this type of metal. It was not found in the literature evidences that this polymer was synthesized before.
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S. Benjamín Valdez, G. Navor Rosas, B. Mónica Carrillo, L. Tezozomoc Pérez, Tetsuya Ogura, G. Celia Beltrán, J. Miguel and G. Beltrán
A corrosion study of the intra‐uterine device, “TCu 380 A”, was made using cyclic voltammetry (CV), scanning electron microscopy (SEM) and optical microscopy (OM). Blood plasma…
Abstract
A corrosion study of the intra‐uterine device, “TCu 380 A”, was made using cyclic voltammetry (CV), scanning electron microscopy (SEM) and optical microscopy (OM). Blood plasma, whole blood and artificial uterine fluid were used as corrosive media in order to establish a comparative scheme of the corrosion behaviour of copper in the device. In summary, the results obtained were not only similar to work reported previously, but also provided complementary data for a better understanding of the corrosion problem.
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Hadeel Alhazimeh, Mohamed Ghazi Al-Fandi and Lina M.K. Al-Ebbini
Ascorbic acid (AA) is an essential vitamin for human health. Therefore, fast and cost-effective detecting of AA is essential, whether in human or food samples. The purpose of this…
Abstract
Purpose
Ascorbic acid (AA) is an essential vitamin for human health. Therefore, fast and cost-effective detecting of AA is essential, whether in human or food samples. The purpose of this paper is to develop an electrochemical nanosensor for AA detection.
Design/methodology/approach
The proposed nanosensor was developed by printing carbon nanoparticles ink and silver nanoparticles ink on a polydimethylsiloxane (PDMS) substrate. The surface of the PDMS substrate was first treated by corona plasma. Then, the nanomaterials printer was used to deposit both inks on the substrate. The working electrode surface was modified by drop-casting of carbon nanotubes. Morphological evaluation was applied using scanning electron microscopy and cyclic voltammetry. Also, a potentiostat was used to detect AA by differential pulse voltammetry.
Findings
It has been shown that the developed nanosensor linearly worked at a range of (0–5 mM), with a limit of detection lower than 0.8 mM and a relative standard deviation of 6.6%.
Originality/value
The developed nanosensor is characterized by a simple and cost-effective sensing tool for AA. In particular, the nanomaterials enhanced the nanosensor’s sensitivity due to the high catalytic activity.
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Ilhem Ghodbane, Saida Zougar, Rim Lamari and Rochdi Kherrrat
This paper aims to focus on the development and characterization of a new electrochemical sensor, designed for the detection of methylene blue present in aqueous medium.
Abstract
Purpose
This paper aims to focus on the development and characterization of a new electrochemical sensor, designed for the detection of methylene blue present in aqueous medium.
Design/methodology/approach
This sensor is obtained through the coupling of a polymeric membrane and an ion-sensitive electrode (platinum electrode). The preparation of the polymeric membrane involves the incorporation of a receptor: β-cyclodextrin (β-CD), a polymer (polyvinylchloride) and a plasticizer (dioctylphtalate). Cyclic voltammetry method (CV) was used to investigate the electrical properties of this electrochemical sensor. The effect of the experimental parameters such as dye initial concentration, scan rate, interfering elements presence and additional Nafion membrane presence was investigated in this paper.
Findings
The results are interesting because the developed sensor gives a linear response in concentrations range of 10−13 M–10−3 M with a good correlation coefficient of 0.979 and a detection limit of 10−13 M, which reflects the sensitivity of this sensor to the target element. The sensibility value is equal to 2. 40 µA mol−1 L.
Originality/value
The present study has shown that the modified electrode is a very good candidate in terms of price, sensibility and reproducibility for the construction of the sensitive sensor for the control of wastewater containing methylene blue.
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Ilhem Ghodbane, Rochdi Kherrrat, Saida Zougar, Rim Lamari, Redouane Haddadji and Mohamed Saleh Medjram
The purpose of this work is to explore electrical properties of an electrochemical sensor designed for the detection of malachite green (MG) present in an aqueous solution.
Abstract
Purpose
The purpose of this work is to explore electrical properties of an electrochemical sensor designed for the detection of malachite green (MG) present in an aqueous solution.
Design/methodology/approach
The present sensor consists in the spatial coupling of a polymeric membrane and an ion-sensitive electrode (platinum electrode). The preparation of the polymeric membrane involves the incorporation of an ionophore (D2HPA), a polymer (polyvinylchloride [PVC]) and a plasticizer (dioctyl phthalate [DOP]). Several techniques have been used to characterize this sensor: the cyclic voltammetry, the electrochemical impedance spectroscopy and the optical microscopy. The sensibility, the selectivity and the kinetic study of a modified platinum electrode have been evaluated by cyclic voltammetry.
Findings
The obtained results reveal the possibility of a linear relationship between the current of reduction peaks and MG concentration. A linear response was obtained in a wide-concentration range that stretches from 10−5 to 10−13 mol L−1, with a good correlation coefficient (0.976) and a good detection limit of 5.74 × 10−14 mol L−1 (a signal-to-noise ratio of 3). In addition, the voltammetric response of modified electrode can be enhanced by adding a layer of Nafion membrane. Under this optimal condition, a linear relationship was obtained, with a correlation coefficient of 0.986 and a detection limit of 1.92 × 10−18 mol L−1.
Originality/value
In the present research, a convenient, inexpensive and reproducible method for the detection of MG was developed. The developed sensor is capable of competing against the conventional techniques in terms of speed, stability and economy.
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Abdulrahman Al-Shami, Rami Joseph Oweis and Mohamed Ghazi Al-Fandi
This paper aims to report on the development of a novel electrochemical amperometric immunosensor to diagnose early hepatocellular carcinoma (HCC) by detecting the Midkine (MDK…
Abstract
Purpose
This paper aims to report on the development of a novel electrochemical amperometric immunosensor to diagnose early hepatocellular carcinoma (HCC) by detecting the Midkine (MDK) biomarker.
Design/methodology/approach
Anti-Midkine antibodies were immobilized covalently through carbodiimides chemistry on carbon screen-printed electrodes modified with carboxylated multi-walled carbon nanotubes. The development process was characterized using cyclic voltammetry, electrochemical impedimetric spectroscopy, Fourier transform infrared spectroscopy and atomic force microscopy. Differential pulse voltammetry was used to investigate the immunosensor performance in detecting MDK antigen within the concentration range of 1 pg/ml to 100 ng/ml.
Findings
MDK immunosensor exhibited high sensitivity and linearity with a detection limit of 0.8 pg/ml and a correlation coefficient of 0.99. The biosensor also demonstrated high selectivity, stability and reproducibility.
Originality/value
The developed MDK immunosensor could be a promising tool to diagnose HCC and reduce the number of related deaths.
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