• Journal of Electrochemical Science and Technology
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• v.4 no.1
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• pp.41-45
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• 2013

Platinum is a well known element which shows a significant electrocatalytic activity in many important applications. In glucose sensor, because of the poisoning effect of reaction intermediates and the low surface area, the electrocatalytic activity towards the glucose oxidation is low which cause the low sensitivity. So, we fabricate a nanoporous PtZn alloy electrode by deposition-dissolution method. It provides a high active surface and a large enzyme encapsulating space per unit area when it used for an enzymatic glucose sensor. Glucose oxidase was immobilized on the electrode surface by capping with PEDOT composite and PPDA. The composite and PPDA also can exclude the interference ion such as ascorbic acid and uric acid to improve the selectivity. The surface area was determined by cyclic voltametry method and the surface structure and the element were analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX), respectively. The sensitivity is $13.5{\mu}A/mM\;cm^2$. It is a remarkable value with such simply prepared senor has high selectivity.

• KSBB Journal
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• v.13 no.3
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• pp.244-250
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• 1998

Flow-injection analysis (FIA) for on-line monitoring of glucose and acetate are described and employed in E.coli fermentation process. Glucose oxidase (GOD) for the detection of glucose is immobilized on epoxy polymer support, which is packed in a small cartirdge, and applied to a GOD-FIA system. The detection of acetate is based on the inhibition of acetate to the oxidation of sarcosine by sarcosine oxidase (SOD). SOD is also immobilized on epoxy polymer support and used for a SOD-FIA system. GOD-FIA system is characterized as well as SOD-FIA system by the investigation of the effects of pH, temperature and metabolites in samples on the peak height. GOD-FIA and SOD-FIA systems were also applied for on-line On-line measurements buy FIA measurements by FIA were in god agreement with off-line measurements.

• Journal of Electrochemical Science and Technology
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• v.2 no.2
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• pp.124-129
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• 2011

A simple process of fabricating micropillar structure and its influence upon enhancing electrochemical biosensor response were studied in this work. Conducting polymer PEDOT was used as a base material in formulating a composite with PVA. Micro porous PC membrane filter was used as a template for the micropillar of the composite on ITO electrode. This structure could provide plenty of encapsulating space for enzyme species. After dosing enzyme solution into this space, Nafion film tent was cast over the pillar structure to complete the micropillar cavity structure. In this way, the encapsulation of enzyme could be accomplished without any chemical modification. The amount of enzyme species was easily controllable by varying the concentration of the dosing solution. The more amount of enzyme is stored in the sensor, the higher the electrochemical response is produced. One more reason for the sensitivity improvement comes from the large surface area of the micropillar structure. Application of 0.7 V produced the best current response under the condition of pH 7.4. This biosensor showed linear response to the glucose in 0.1~1 mM range with the average sensitivity of $14.06{\mu}A/mMcm^2$. Detection limit was 0.01 mM based on S/N = 3.

• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.82-88
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• 1997

To produce biopolymer, Metarrhizium anisopliae (Metschn.) Sorok was cultured in a medium containing glucose 1.0%, sucrose 2.0% , soluble starch 1.0%, yeast extract 0.5%, polypeptone 0.05%, K$_{2}$HPO$_{4}$ 0.1% MgSO$_{4}$ $\CDOT $ 7H$_{2}$O 0.02%. The culture broth was centrifuged and the polymer was harvested by adding methanol to the culture supermatant. When three times of methanol was added, the polymer was coagulated and precipitated. Then it was further purified through successive SK-1B, SA-20P, HP-20 column chromatographies. This polymer was designated as Biopolymer YU-122.C:H ratio of this Biopolmer YU-122 was 1:2 and small amount of N is detected by CHN analyzer. Glucose and glactose are main components of this polymer. Average molecular weight of this biopolymer was 1.7%$\times $10$^{6}$ by Sepharose 4B gel permeation chromatography. Optimal condition for biopolymer production was investigated. When 5% of mannitol was used as a carbon source, and polypepton as a N source, highest productivity of biopolymer was achieved. C/N ratio as nutrient was also a major factor in polymer production and its optimal ratio was 3.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.539-545
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• 2014

Styrene-acrylamide co-polymer was immobilized on porous partially sub-$2{\mu}m$ silica monolith particles and inner surface of fused silica capillary ($50{\mu}m$ ID and 28 cm length) to result in ${\mu}LC$ and CEC stationary phases, respectively, for separation of anomeric D-glucose derivatives. Reversed addition-fragmentation transfer (RAFT) polymerization was incorporated to induce surface polymerization. Acrylamide was employed to incorporate amide-functionality in the stationary phase. The resultant ${\mu}LC$ and CEC stationary phases were able to separate isomers of D-glucose derivatives with high selectivity and efficiency. The mobile phase of 75/25 (v/v) acetonitrile (ACN)/water with 0.1% TFA, was used for HPLC with a packed column (1 mm ID, 300 mm length). The effects of pH and ACN composition on anomeric separation of D-glucose in CEC have been examined. A mobile phase of 85/15 (v/v) ACN/30 mM sodium acetate pH 6.7 was found the optimized mobile phase for CEC. The CEC stationary phase also gave good separation of other saccharides such as maltotriose and Dextran 1500 (MW~1500) with good separation efficiency (number of theoretical plates ~300,000/m).

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.603-606
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• 2005

Ralstonia eutropha NCIMB 11599 and ATCC 17699 were grown, and their productions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] compared. In flask cultures of R. eutropha NCIMB 11599, cell concentration, P(3HB-co-4HB) concentration and polymer content decreased considerably with increases in the ${\gamma}-butyrolactone$ concentration, and the 4HB fraction was also very low (maximum 1.74 mol%). In fed-batch cultures of R. eutropha NCIMB 11599, glucose and ${\gamma}-butyrolactone$ were fed as the carbon sources, under a phosphate limitation strategy. When glucose was fed as the sole carbon source, with its concentration controlled using an on-line glucose analyzer, 86% of the P(3HB) homopolymer was obtained from 201g/L of cells. In a two-stage fed-batch culture, where the cell concentration was increased to 104g/L, with glucose fed in the first step and constant feeding of ${\gamma}-butyrolactone$, at 6g/h, in the second, final cell concentration at 67h was 106g/L, with a polymer content of 82%, while the 4HB fraction was only 0.7mol%. When the same feeding strategy was applied to the fedbatch culture of R. eutropha ATCC 17699, where the cell concentration was increased to 42 g/L, by feeding fructose in the first step and ${\gamma}-butyrolactone$ (1.5g/h) in the second, the final cell concentration, polymer content and 4HB fraction at 74h were 51g/L, 35% and 32 mol%, respectively. In summary, R. eutropha ATCC 17699 was better than R. eutropha NCIMB 11599 in terms of P(3HB-co-4HB) production with various 4HB fractions.

• Journal of the Korean Society of Safety
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• v.5 no.1
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• pp.7-18
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• 1990

This study measured the smouldering temperature of dust layer for various combustible natural polymer material by practical apparatus. The dust layer was either put on the preheated plate of constant temperature, or formed with cylinderical metal sleeve of various diameters and depths at room temperature and then heated up to a pre-determined smouldering temperature. Plots of arrival times versus smouldering temperature were made to compare the smouldering characteristics with kinds of dusts. The natural polymer material was divided into theree groups by characteristics of smouldering mechanism. This groups are cellulose group, lipide group and glucose group.

• Macromolecular Research
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• v.13 no.4
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• pp.356-361
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• 2005

• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.56-61
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• 2011

In the present study, glucose-sensitive hydrogels using phenylboronic acid (PBA) without glucose oxidase and catalase were prepared. The swelling-shrinking behavior of the hydrogel according to the variation of pH and glucose and ionic concentrations was investigated. The swelling ratio of the hydrogel containing PBA increased with increasing the glucose concentration and the volume was very sensitively varied with the pH. However, the ionic concentration did not change significantly the relative swelling ratio on the hydrogel, indicating that the hydrogel was dimensionally stable.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.277-279
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• 1998

An extracellular polymer (exo-polymer) with hepatoprotective properties was produced after a 6-day submerged mycelial culture of Ganoderma lucidum WK-003. The glutamic pyruvic transaminase (GPT) activities in the serum of intoxicated Sprague-Dawley rats were decreased from 871 to 263 by the oral administration of the exo-polymer (20 mg/kg/day) for 4 consecutive days. Rhamnose, arabinose, xylose, mannose, galactose, and glucose were found in the exo-polymer along with aspartic acid, glutamic acid, histidine, serine, glycine, arginine, alanine, tryptophan, valine, phenylalanine, isoleucine, and leucine.