• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1450-1454
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• 2007

This paper presents a microfabricated Clark-type sensor which exactly can measure dissolved oxygen in the cell containing solution. We designed, fabricated, and characterized a microfabircated Clark-type oxygen sensor for measuring dissolved oxygen. The microfabricated oxygen sensor consists of 3-electrodes on a glass substrate, a FEP (Fluorinated ethylene propylene) oxygen-permeable membrane, and PDMS (Polydimethylsiloxane) reservoir for storing sample solution. Thin-film Ag/AgCl was employed as a reference electrode and its durability was verified by obtaining a stable open circuit potential for 2 hours against a commercial Ag/AgCl electrode and a stable cyclic voltammetry curve. Selectivity, response time, and linearity of the fabricated oxygen sensor were also verified well by cyclic voltammetry and amperometry depending. The fabricated oxygen sensor showed a 90% response time of 40sec and an excellent linearity with a correlation coefficient of 0.994.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.447-448
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• 2005

Recently, organic light emitting diodes(OLEDs) is widely used as one of the information display techniques. We synthesized 2-(2-hydroxyphenyl)benzoxazole($Zn(HPB)_2$). We studied the luminescent properties of OLEDs using $Zn(HPB)_2$. The ionization potential(IP) and the electron affinity(EA) of $Zn(HPB)_2$ investigated using cyclic-voltammetry(C-V). The JP, EA and Eg were 6.5eV, 3.0eV and 3.5eV, respectively. The PL and EL spectra of $Zn(HPB)_2$ were observed at the wavelength of 4S0nm. We used $Zn(HPB)_2$ as an emitting layer and hole blocking layer. At the experiment about hole blocking effect, we inserted $Zn(HPB)_2$ between emitting material layer(EML) and cathode, and hole transport layer(HTL) and emitting material layer(EML). We measured current density-voltage and luminance-voltage characteristics at room temperature.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.185-189
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• 2016

Among many kinds of bioaffinity sensors, the avidin-biotin system has been widely used in a variety of biological applications due to the specific and high affinity interaction of the system. In this work, gold nanorods with high surface area were explored as electrodes in order to amplify the signal response from the avidin-biotin interaction which can be further utilized for avidin-biotin biosensors. Electrochemical performance of electrodes modified with nanorods and functionalized with avidin in response to interactions with biotin at various concentrations using $[Fe(CN)_6]^{3-/4-}$ couple as the redox probe were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A very low biotin concentration of less than 1 ng/mL could be detected using the electrodes modified with nanorods.

• Analytical Science and Technology
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• v.15 no.2
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• pp.97-101
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• 2002

Co(II) complexes with tridentate Schiff base-NOIPH and tetradentate Schiff base-$NOTDH_2$ and $TNBPH_4$ were synthesized. The redox process of the complexes in DMF solution containing 0.1M TBAP was investigated at glassy carbon electrode by cyclic voltammetry and differential pulse voltammetry techniques. Reduction step of [Co(II)$(NOIP)_2$] and [Co(II)$(H_2O)_2$] complexes were observed in two step as one electron process of irreversible or quasi-reversible and diffusion-controlled reaction. [$Co(II)_2$(TNBP)] complex was observed in one step as one electron process of quasi-reversible and diffusion-controlled reaction.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.44-49
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• 2014

We were investigated by cyclic voltammetry to the stability through the electrochemical characteristics of phospholipid(L-${\alpha}$-phosphatidylethanolamine, LAPE) monolayer LB films. LAPE monolayer LB films was deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties was measured by cyclic voltammetry with a three-electrode system in 0.5 N, 1.0 N, 1.5 N and 2.0 N $KClO_4$ solution. The measuring range is continuously oxidized to 1650 mV, with an initial potential of -1350 mV was reduced. Scanning rates of 50, 100, 150, 200, and 250 mV/s was set. As a result, LB monolayer films of LAPE was appeared on irreversible processes by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of LAPE was calculated 195, 15.9, 5.75, 1.38 and $0.754cm^2s^{-1}{\times}10^{-9}$ at 0.01 N, 0.05 N, 0.10 N, 0.15 N and 0.20 N $KClO_4$ solutions, respectively.

• Journal of the Korean Chemical Society
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• v.58 no.2
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• pp.153-159
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• 2014

Herein, the cyclic voltammetric (CV) investigations of structurally similar bisnitrocompounds (N3, N4, N5, N6, having different-$CH_2$-spacer length) is presented. CV study offered interesting interactional possibilities of bisnitrocompounds with chicken blood ds.DNA at physiological pH 4.7 and human body temperature, 310 K. The results indicated strong interaction by these symmetric molecules with ds.DNA and strength of binding is found to depend on length of $CH_2$ spacer group in their molecular structure. Thermodynamics derived from electrochemical binding parameters also favored the irreversible interactions. Moreover, threading intercalation mode of binding is suggested based on thermodynamic and kinetic binding parameters extracted from CV studies.

• Journal of Electrochemical Science and Technology
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• v.4 no.3
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• pp.93-101
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• 2013

The electrodeposition of indium onto a copper electrode from an aqueous sulfate solution containing $In^{3+}$ was studied by means of cyclic voltammetry and chronoamperometry. Reduction and oxidation of indium on copper were investigated by using cyclic voltammograms at different negative limiting potentials and at different scan rates in cumulative cycles. Cyclic voltammograms indicated that reduction and oxidation processes of indium could involve various reactions. Chronoamperometry was carried out to analyze the nucleation mechanism of indium in the early stage of indium electrodeposition. The non-dimensional plot of the current transients at different potentials showed that the shape of the plot depended on the applied potential. The nucleation of indium at potential step of -0.6~-0.8 V was close to progressive nucleation limited by diffusion. However the non-dimensional plot of current transients for the indium nucleation showed different behaviors from theoretical curves at the potential step lower than -0.8 V.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.920-923
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• 2004

We have investgated on the monolayer LB film of BASH-DMPC mixture on an ITO for the photoisomerization by light irradiation. We measured electrochemical properties by using cyclic voltammetry with a three-electrode system, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode in $NaClO_4$ solution at a variable concentration and monolayer LB films. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150 and 200 mV/s. As a results, LB films of 8A5H-DMPC appeared reversible process caused by the reduction-oxidation current from the cyclic voltammogram.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.392-397
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• 1995

o-Phenylenediamine (o-PD) was electropolymerized on glassy carbon electrodes under a potential cycling condition. The resulting polymer films mediated electrons for the reduction of molecular oxygen at pH=1.0. It was found from the RDE, RRDE, and cyclic voltammetry experiments that the modified electrodes reduce oxygen to hydrogen peroxide at about 300 mV lower potential than the bare glassy carbon electrode. The polymer film consisted of more than two components. Among those, only one component was active in oxygen reduction, which was formed mainly in the earlier stage of the electropolymerization. 2,3-Diaminophenazine, a cyclic dimer of o-PD, was also active in the oxygen reduction reaction, from which it was suggested that the active polymeric component has a structural unit similar to the cyclic dimer. Finally, the electropolymerization mechanism for the formation of the active and inactive components has been proposed.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.114-121
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• 1997

The positive active material for polymer film-battery was prepared by using polyphenlenediamine(PPD) synthesized in our lab. and 2,5-dimercapto-1,3,4-thiadiazole(DMcT) with various mixture ratio. The transference measurement of surface morphology and thermal stability of the prepared composite film was carried out by using SEM and TGA, respectively. Electrochemical property and electrical conductivity of the composite film were also measured by using cyclic voltammetry and four-probe method in dry box, respectively. The thermal stability of prepared composite film was up to $200^{\circ}C$. The electrical conductivity of the composite film increased and showed the highest value(about 3 S/cm) when doped at 0.4% $LiCIO_4$ solution. And we could confirm that DMcT was effective on reactivation of PPD through cyclic voltammogram.