• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.891-898
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• 2008

In this paper, we have studied on the possibilities of the biomaterial detection using single-walled carbon nanotube (SWNT) based on interdigital capacitors. For the four different configurations, such as interdigital capacitor, SWNT in the $5\;{\mu}m$ gap interdigital capacitor, biotinlated SWNT, and biotin and sreptavidin immobilization cases, the resonant frequency has been measured as 10.02 GHz, 11.02 GHz, 10.82 GHz, and 10.22 GHz, respectively. Assuming that the resonant frequency reflects the capacitance changes due to binding of two-different permittivity biomaterials, we have suggested an equivalent circuit model based on measured results, confirming the capacitance changes. For biotinlated SWNT and biotin-streptavidin immobilization cases, the capacitances are $C_b=0.55\;pF$ and $C_s=0.95\;pF$. In this work, we experimentally demonstrated that the specific biomaterial binding causes the capacitance change and therefore this gives rise to resonant frequency. In conclusion, we confirmed the sufficient possibility as CNT biosensor because an analyte biomaterial(streptavidin) binding arouses a considerable resonant frequency change.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.465-466
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• 2009

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.254.2-254.2
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• 2003

For many viruses, -1 ribosomal frameshifting regulate protein synthesis using an RNA pseudoknot. The integrity of pseudoknot stability and structure is the important feature for efficient frameshifting. Thus, small molecules interacting with viral RNA pseudoknots would be potential antiviral agents targeting\ulcorner frameshifting system in viruses. X-ray structure of RNA pseudoknot complexed with biotin has been reported, in which biotin is bound at the interface between the pseudoknot's stacked helices. (omitted)

• Journal of Nutrition and Health
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• v.8 no.1
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• pp.9-10
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• 1975

• KOREAN POULTRY JOURNAL
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• v.17 no.1 s.183
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• pp.64-65
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• 1985

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.137-142
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• 2004

In this study, a simple procedure is described for patterning biotin on a glass substrate and then selectively immobilizing proteins of interest onto the biotin-patterned surface. Microcontact printing (CP) was used to generate the micropattern of biotin and to demonstrate the selective immobilization of proteins by using enhanced green fluorescent protein (EGFP) as a model protein, of which the C-terminus was fused to a core streptavidin (cSA) gene of Streptomyces avidinii. Confocal fluorescence microscopy was used to visualize the pattern of the immobilized protein (EGFP-cSA), and surface plasmon resonance was used to characterize biological activity of the immobilized EGFP-cSA. The results suggest that this strategy, which consists of a combination of $\mu$CP and cSA-fused proteins. is an effective way for fabricating biologically active substrates that are suitable for a wide variety of applications. one such being the use in protein-protein assays.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.112-117
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• 2004

The performance of an immuno-analytical system can be assessed in terms of its analytical sensitivity, i.e., the detection limit of an analyte, which is determined by the amount of analyte molecules bound to the capture antibody that has been immobilized onto a solid surface. To increase the number of the binding complexes, we have investigated a site-directed immobilization of an antibody that has the ability to resolve a current problem associated with a random arrangement of the insolubilized immunoglobulin. The binding molecules were chemically reduced to produce thiol groups that were limited at the hinge region, and then, the reduced products were coupled to biotin. This biotinylated antibody was bound to a streptavidin-coated surface via the streptavidin-biotin reaction. This method can control the orientation of the antibody molecules present on a solid surface and also can significantly reduce the possibility of steric hindrance in the antigen-antibody reactions. In a two-site immunoassay, the introduction of the site-directly immobilized antibody as the capture enhanced the sensitivity of analyte detection approximately 10 times compared to that of the antibody randomly coupled to biotin. Such a novel approach would offer a protocol of antibody immobilization in order for the possibility of constructing a high performance immunochip.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.986-992
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• 2007

This paper presents the fabrication and characterization of carbon films pyrolyzed with various photoresists for bioMEMS applications. To verify the usefulness of pyrolyzed carbon films as an electrode material in an electrochemical biosensor developed by the authors, interactions between avidin and biotin on the pyrolyzed carbon film were studied via electrochemical impedance spectroscopy based on electrostatic interactions between avidin and negatively-charged ferricyanide. The pyrolyzed carbon films were characterized using a surface profiler, a precision semiconductor parameter analyzer, a nanoindentor, scanning electron microscopy, and atomic force microscopy. Amine conjugated biotin was immobilized on the electrode using EDC/NHS as crosslinkers after $O_2$ plasma treatment to enhance functional groups on the carbon electrode pyrolyzed at $1000^{\circ}C$ with AZ9260. The detection of avidin binding with different concentrations in a range of 0.75 nM to $7.5\;{\mu}M$ to the pyrolyzed carbon electrode modified with biotin was carried out by measuring the electrochemical impedance change. The results show that avidin binds to the biotin on the electrode not by non-specific interaction but by specific interaction, and that EIS successfully detects this binding event. Pyrolyzed carbon films are a promising material for miniaturization, integration, and low-cost fabrication in electrochemical biosensors.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.16-19
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• 1996

The yeast strains isolated for Choungju brewing in the previous report were examined for their microbiological characteristics, together with some comparative tests with Japanese sake yeasts. The isolates KP-16, 21 and 54 were identified as the strains belong to Saccharomyces cerevisae according to the morphological and physiological properties described in Lodder's 'The Yeasts - A texanomic study'. The isolates were grouped into the pink-colored strains by 2,3,5-tripheny tetrazolium chloride over-lay method. The strains KP-16 and 21 were found to be distinguished from the strain KP-54 in aspects of fermentation of sugars, assimilation of carbon sources, and pellicle formation on malt extract broth. ${\alpha}-methyl-D-glucoside$ was not assimilated or fermented by the isolated yeast strains and this is one of the different characters from the Japanese sake yeasts. The isolated strains appeared to have the requirements for biotin and pantothenate, and to have higher tolerance to ethanol than the Japanese sake yeasts. The biotin requirement was not found in the sake yeasts.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.346-351
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• 2008

This study develops DNA array which can detect specific sequence of human papilomavirus (HPV) by using lateral flow membrane assay which is usually used for point of care test including pregnant diagnosis. Principle of HPV DNA array is as follow; fixing DNA probe which is peculiar to HPV type 6, 11, 16, 18, 31, 45 on a surface of lateral flow membrane and inducing hybridization response between probe and HPV PCR products which is obtained by using biotin-labeled MY09/l1 primers. And then, we can see the result of DNA hybridization that streptavidin labelled colloidal gold is responded with hybrid biotin. Lateral flow membrane array developed in this study confirms major HPV type economically and conveniently compared with existing HPV DNA chip method.