• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.64.2-65
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• 2000

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• 한국전기전자재료학회논문지
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• 제16권6호
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• pp.496-500
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• 2003

Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface[1]. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency(ΔF) and resonant resistance(R). The redox process of viologen was observed with resonant frequency(ΔF).

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 추계학술발표대회
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• pp.92-99
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• 2000

In this study biofuel cell is classified into 5 generation fuel cell system based on structural and structural difference. I optionally named the biofuel cell with electron mediators prototype, that with electrochemical active bacterium 2nd generation, that with modified electrode with NR 3rd generation, that with catalytic active electrode 4th generation, and that using air as a catholyte instead of ion selective membrane and cathode, respectively. The electricity production was compared among 5 types biofuel cell and was confirmed to be $50-100\%$ higher in 4th and 5th generation than in 1st to 3rd generation.

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• 제5권5호
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• pp.631-636
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• 2018

Extraction of photosynthetic currents from thylakoids was studied using micro pillar structured electrode. Thylakoids were isolated from spinach leaves, and the size and shape of thylakoids were estimated from scanning electron microscopy images. Based on the geometry information of thylakoids, micro pillar shaped electrode was designed and fabricated using metal-assisted chemical etching of silicon wafers. Influence of photovoltaic effect on the silicon-based micro pillar electrode was confirmed to be negligible. Photosynthetic currents were measured in a three-electrode setup with an electron mediator, potassium ferricyanide. Photosynthetic currents from micro pillar electrodes were enhanced compared with the currents from flat electrodes. This indicates the significance of the enhanced contact between thylakoids and an electrode for harvesting photosynthetic electrons.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.62-72
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• 2015

This study investigates the in-situ implementation of bio-regenerated iron mineral catalyst to remove explosive compounds in ground water at a military shooting range in operation. A bio-regenerated iron mineral catalyst was synthesized using lepidocrocite (iron-bearing soil mineral), iron-reducing bacteria Shewanella putrefaciens CN32, and electron mediator (riboflavin) in the culture medium. This catalyst was then injected periodically in the ground to build a redox active zone acting like permeable reactive barrier through injection wells constructed at a live fire military shooting range. Ground water and core soils were sampled periodically for analysis of explosive compounds, mainly RDX and its metabolites, along with toxicity analysis and REDOX potential measurement. Results suggested that a redox active zone was formed in the subsurface in which contaminated ground water flows through. Concentration of RDX as well as toxicity (% inhibition) of ground water decreased in the downstream compared to those in the upstream while concentration of RDX reduction products increased in the downstream.

• 공업화학
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• 제1권2호
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• pp.107-115
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• 1990

Glucose의 redox 반응에 의한 새로운 인슐린 방출계를 5, 5'-dithiobis(2-nitrobcnzoic acid)의 disulfide 결합을 이용해 인슐린을 pmma 막과 glucose oxidase에 고정화시켜 합성하였다. glucose와 glucose dehydrogenase 및 glucose oxidise와의 산화반응에 의해 disulfide 결합이 파괴되어 막과 효소로부터 인슐린이 방출된다. enzyme cofact들(nicotinamide adenin dinucleotide와 flavin adenin dinucleotide)을 coimmobilization 시켜 membrane device에 대해 electron mediator로 작용하도록 하여 glucose의 농도 민감성을 향상시켰고 protein device에 대해서는 glucose oxidase에 인슐린을 직접 고정화시켜 민감성을 더욱 향상시켰다. 이 두 가지 계들은 glucose 특이성을 나타내며 방출된 인슐린은 생체인슐린과 구분되지 않았다. 방출인슐린의 생리활성은 생체인슐린의 81%였다.

• 한국환경농학회지
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• 제31권1호
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• pp.24-29
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• 2012

BACKGROUND: In recent years, microbial fuel cells (MFCs) have emerged as a promising technology for recovering renewable energy from waste biomass, especially wastewater. In this study, the possibility of bioelectricity generation in two chambered mediator-less microbial fuel cells (MFCs) was successfully demonstrated using fermentable and non-fermentable substrates. METHODS AND RESULTS: Two different electron acceptors have been tested in the cathode chamber for the effects of reducing agent on the power generation in MFCs. The average voltages of $0.26{\pm}0.014$ V and $0.36{\pm}0.02$ V were achieved with acetate using oxygen and potassium ferricyanide as reducing agent, respectively. Similarly, with glucose the average voltages of $0.256{\pm}0.05$ V and $0.340{\pm}0.04$ V were obtained using oxygen and ferricyanide, respectively. Using potassium ferricyanide as the reducing agent, the power output increases by 39 and 43% with acetate and glucose, respectively, as compared to the dissolved oxygen. Slightly higher coulombic efficiency (CE%) was obtained in acetate as compared to MFCs operated with glucose. The maximum power densities of 124 mW/$m^2$ and 204 mW/$m^2$ were obtained using dissolved oxygen and $K_3Fe(CN)_6$, respectively. CONCLUSION(s): This study demonstrates that power generation from the MFCs can be influenced significantly by the different types of catholyte. Relatively higher CE was obtained with $K_3Fe(CN)_6$. Thus, application of $K_3Fe(CN)_6$ as the catholyte can be vital for scaling uppower generation from the MFCs forreal time applications.

• Journal of Electrochemical Science and Technology
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• 제11권3호
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• pp.310-317
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• 2020

A development of disposable strip-type galactose sensor for point-of-care testing (POCT) was studied, which was constructed using screen-printed carbon electrodes. Galactose levels were determined by the redox reaction of galactose oxidase in the presence of potassium ferricyanide as an electron transfer mediator in a small sample volume (i.e., less than 1 µL). The optimal performance of biosensor was systematically designated by varying applied potential, operating pH, mediator concentration, and amount of enzyme on the electrode. The sensor system was identified as a highly active for the galactose measurement in terms of the sensitivity (slope = 4.76 ± 0.05 nA/µM) with high sensor-to-sensor reproducibility, the linearity (R² = 0.9915 in galactose concentration range from 0 to 400 µM), and response time (t_95% = <17 s). A lower applied potential (i.e., 0.25 V vs. Ag/AgCl) allowed to minimize interference from readily oxidizable metabolites such as ascorbic acid, acetaminophen, uric acid, and acetoacetic acid. The proposed galactose sensor represents a promising system with advantage for use in POCT.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.526-532
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• 2016

In this study, we synthesized a mediator immobilized biocatalyst([FCA/GOx]/PEI/CNT) by surface modification using ferrocene carboxylic acid(FCA), and evaluated its performance as anode catalyst for biofuel cell. Through the application of FCA on glucose oxidase (GOx), the free amine groups on the lysine residue of GOx surface reacted with carboxylic acid of FCA and make amide bond between GOx and FCA. As the result of that, the electron transfer of catalyst was increased up to 1.91 times($0.468mA{\cdot}cm^{-2}$) than the catalyst without surface modification (GOx/PEI/CNT), and high maxium power density of $1.79mA{\cdot}cm^{-2}$ was gained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.86-87
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• 2007

An amperometric glucose biosensor has been developed using viologen derivatives as electron mediator of glucose oxidase (GOD) at Au electrode. Highly stable self assembled monolayer (SAM) of thiol-based viologen is immobilized onto the Au electrode followed byGOD is immobilized onto the viologen modified electrode. This biosensor response to glucose was evaluated amperometrically in the potential of -300 mV. Upon immobilization of glucose oxidase onto the viologen modified-electrode, the biosensor showed rapid response towards glucose. Experimental conditions influencing the biosensor performance such as, pH, potential were optimized and assessed. This biosensor offered an excellent electrochemical response for glucose concentration below ${\mu}mol$ level with high sensitivity and selectivity and short response time. The levels of the RSD's (< 5 %) for the entire analyses reflected the highly reproducible sensor performance. Using the optimized a linear relationship between current and glucose concentration was obtained up to $4.5{\times}10^{-4}$ M. In addition, this biosensor showed well reproducibility and stability.