• Analytical Science and Technology
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• v.19 no.1
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• pp.58-64
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• 2006

A mugwort-tissue-based modified carbon paste electrode was constructed for the amperometric detection of hydrogen peroxide and its electrochemical properties are described. Especially the amperometric signal was very stable and bigger than any other enzyme electrode studied in this lab. The effect of tissue composition on the response was linear within the wide range of experiment and the linearity of Lineweaver-Burk plot showed that the sensing process of the biosensor is by enzymatic catalysis. And pH dependent current profile connoted that two isozymes are active in this system.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.35-40
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• 2022

In this study, the average particle size of silver powder was 2㎛, 7㎛, and a mixture of these (50:50wt%), three kinds of silver pastes were prepared. In addition, as a result of examining the viscosity and viscoelasticity of the three silver pastes, TGA measurement, resistance change according to strain, and change in surface structure of the electrode, the following conclusions were obtained. Summarizing these results, it was found that it is most desirable to have a particle size of about 2㎛ in order to minimize the change in resistance due to strain.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.75.1-75.1
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• 2010

Dye sensitized solar cells(DSSCs) have been extensively studied due to their various advantages such as low production cost, colorful design, and eco-friendly process. Long optical path length is one of the most effective method to improve light harvest efficiency for DSSCs. Multi-layered $TiO_2$ nano-structured film with scattering layer has been studied to generate scattering effect by many researchers. It was expected that the difference of refractive index between $TiO_2$ particles and glass frit would generate the light scattering effect and provide the long optical path length. Therefore, to enhance the scattering effect, the frits of $Bi_2O_3-B_2O_3$-ZnO glass system that has the different refractive index were added to $TiO_2$ pastes in this study. First of all, the absorbance and haze factor of $TiO_2$ electrode with dyes and the refractive index of glass frit and $TiO_2$ were measured, respectively. To study the effect of frits, the efficiencies of DSSCs added glass frit and without glass frit were compared. Our results showed slightly higher efficiency with the different absorbance and haze factor of $TiO_2$ and glass frit. It was considered that the light scattering effect would be improved with adding frits to $TiO_2$ paste. Our preliminary studies will be useful for increasing efficiency of DSSCs.

• Journal of the Korean Electrochemical Society
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• v.8 no.1
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• pp.6-11
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• 2005

Direct borohydrides fuel cell (DBFC) was emerged to complement the problem of DMFC's low performance and methanol crossover to the cathode and to apply the fuel cell to portable and mobile devices. In this study, the characteristics of novel catalysts was tested to establish the electrode preparation process of DBFC. Pt black and carbon supported-Pt by paste method were used as the cathode catalysts. Pt black, carbon supported-Au and $AB_5$ alloy were used as the anode catalysts. The characteristics of the electrodes were analyzed by XRD, SEM, EDS. The performance test of single cell using the electrodes were carried out in order to evaluate the electrode performance. In the result, the maximum power output was obtained as 366 mW/mg when using Pt/C as anode and cathode catalysts.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.329-334
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• 2013

A pine needle-embedded graphite enzyme electrode, of which bonding agent is CSM rubber, was newly designed and its electrochemistry was studied based on the amperometry. It involved a ground green leaves of pine tree as a zymogen together with electrochemical mediator, ferrocene within the paste. The plots of ln($i(1-e^{nf{\eta}})$) vs. ${\eta}$ and Lineweaver-Burk at the low potential (-100 to -500 mV) showed good linearities indicating that the amperometric response is by the catalytic power of pine peroxidase. Electrochemical parameters obtained, symmetry factor (${\alpha}$, 0.17), limiting current ($i_1$, 1.99 $A/cm^2$), exchange current density ($i_0$, $5.86{\times}10^{-5}\;A/cm^2$), Michaelis constant ($K_M$, $1.68{\times}10^{-3}$ M) and many others showed that pine peroxidase discharges the role of catalyst quantitatively on the electrode surface. Those proved that the practical use of pine peroxidase is promising in place of the marketed.

• Journal of Electrochemical Science and Technology
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• v.12 no.2
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• pp.173-187
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• 2021

In the present research, a simple electrochemical sensor based on a carbon paste electrode (CPE) modified with ZnO-Zn₂SnO₄-SnO₂ and graphene (ZnO-Zn₂SnO₄-SnO₂/Gr/CPE) was developed for the direct, simultaneous and individual electrochemical measurement of Acetaminophen (AC), Caffeine (Caf) and Ascorbic acid (AA). The synthesized nano-materials were investigated using scanning electron microscopy, X-ray Diffraction, Fourier-transform infrared spectroscopy, and electrochemical impedance spectroscopy techniques. Cyclic voltammetry and differential pulse voltammetry were applied for electrochemical investigation ZnO-Zn₂SnO₄-SnO₂/Gr/CPE, and the impact of scan rate and the concentration of H⁺ on the electrode's responses were investigated. The voltammograms showed a linear relationship between the response of the electrode for individual oxidation of AA, AC and, Caf in the range of 0.021-120, 0.018-85.3, and 0.02-97.51 μM with the detection limit of 8.94, 6.66 and 7.09 nM (S/N = 3), respectively. Also, the amperometric technique was applied for the measuring of the target molecules in the range of 0.013-16, 0.008-12 and, 0.01-14 μM for AA, AC and, Caf with the detection limit of 6.28, 3.64 and 3.85 nM, respectively. Besides, the ZnO-Zn₂SnO₄-SnO₂/Gr/CPE shows an excellent selectivity, stability, repeatability, and reproducibility for the determination of AA, AC and, Caf. Finally, the proposed sensor was successfully used to show the amount of AA, AC and, Caf in urine, blood serum samples with recoveries ranging between 95.8% and 104.06%.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2613-2618
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• 2012

Hydrothermal route have been used in different conditions for preparation of $Ni(OH)_2$ nanostructures. The NiO nanoparticles were obtained by calcining the $Ni(OH)_2$ precursor at $450^{\circ}C$ for 2 h. The effect of sodium dodecyl sulfonate (SDS) as surfactant on the morphology and size of $Ni(OH)_2$ nanoparticles were discussed in detail. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize the products. The growth mechanism of the as-synthesized nanostructures was also discussed in detail based on the experimental results. Coming up, the NiO nanoparticle modified carbon paste electrode was applied to the determination of captopril in aqueous solution.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1613-1617
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• 2006

Optimum analytical conditions for cyclic voltammetry (CV) and square wave (SW) stripping voltammetry were determined using mercury-mixed carbon nanotube paste electrode (PE). The results approached the microgram working ranges of SW: 10.0-80.0 $ugL^{-1}$ and CV: 100-700 $ugL^{-1}$ Cd (II); working conditions of 300-Hz frequency, 100 mV amplitude, 1.6 V accumulation potential, 400 sec accumulation time, and 40 mV increment potential. First, analysis was performed through direct assay of cadmium ions deep into the fishs brain core and plant tissue in real time with a preconcentration time of 400 sec. The relative standard deviation of 10.0 $mgL^{-1}$ Cd (II) observed was 0.064 (n = 12) at optimum conditions. The low detection limit (S/N) was set at 0.6 $ugL^{-1}$ ($5.33{\times}10^{-9}$ M). The methods can be used in direct analysis in vivo or in real-time monitoring of plant tissue.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.443-449
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• 2012

A investigation of electrochemical analysis of antibiotics Neomycin ($C_{23}H_{46}N_6O_{13}$) was searched using electrochemical square wave (SW) stripping and cyclic voltammetry (CV) using working sensor of the modified carbon nanotube combination electrodes, optimum diagnostic parameters were searched by anodic stripping, final conditions were attained to working range of 1.0-14.0 ng/L, detection limit (S/N) was found to be 0.6 ng/L. The developed method was discovered to be fitting in quality control in the food, pharmaceutical and other manufacturing sectors.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.997-1002
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• 2006

This report presents a voltammetric assay of dinitrotoluene using a DNA immobilized onto a carbon nanotube paste electrode (PE). The cyclic voltammetry (CV) and square wave (SW) stripping voltammetry parameters of the optimized conditions were obtained. An anodic peak current appeared at 0.3 V (versus Ag/AgCl) in a 0.1-M $NH_4H_2PO_4$ electrolyte solution. The detection limit was found to be $0.6ngL^{-1}$(S/N = 10), within a deposition time of 100 sec.