• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.32 no.6
• /
• pp.459-464
• /
• 2008

We present a novel microcantilever device with nano-interdigitated electrodes (nano-IDEs) and DNA selective immobilization on the nano-IDEs for biosensing applications. Using the nano-IDEs and cyclic voltammetric methods, we have achieved selective immobilization of DNA with submicrometer spatial resolution on a freestanding microcantilever. $70{\sim}500\;nm$-wide gold (Au) nano-IDEs are fabricated on a low-stress SiNx microcantilever with dimensions of $100{\sim}600\;{\mu}m$ in length, and $15{\sim}60\;{\mu}m$ in width, with a $0.5\;{\mu}m$ thickness using electron beam lithography and bulk micromachining. Streptavidin is selectively deposited on one side of the nano-IDEs using cyclic voltammetry at a scan rate of 0.1 V/s with a range of $-0.2{\sim}0.7\;V$ during $1{\sim}5$ cycles. The selective deposition of dsDNA is confirmed by fluorescence microscopy after labeling with YOYO-1 dye.

• The Journal of the Acoustical Society of Korea
• /
• v.24 no.3
• /
• pp.160-165
• /
• 2005

We have developed SH (shear horizontal) surface acoustic wave (SAW) sensors for detection of the immobilization and hybridization of DNA (deoxyribonucleic acid) on the gold coated delay line of transverse SAW devices. The experiments of DNA immobilization and hybridization were performed with 15-mer oligonucleotides (probe and complementary target DNA). The sensor consists of twin SAW delay line oscillators operating at 100 MHz fabricated on $36^{\circ}$ rotated Y-cut $LiTaO_3$ piezoelectric single crystals. The relative change in the frequency of the two oscillators was monitored to detect the hybridization between target DNA and immobilized probe DNA in pH 7.4 PBS (phosphate buffered saline) solution. The measurement results showed a good response of the sensor to the mass loading effects of the DNA immobilization and hybridization with the sensitivity up to $1.55{\cal}ng/{\cal}ml/Hz$.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.8 no.4
• /
• pp.263-267
• /
• 2003

Magnetic nanoparticles prepared from an alkaline solution of divalent and trivalent iron ions could covalently bind protein via the activation of Nethyl-N-(3-dimethylaminopropyl) carbodiimide (EDC). Trypsin and avidin were taken as the model proteins for the formation of protein-nanoparticle conjugates. The immobilized yield of protein increased with molar ratio of EDC/nanoparticie. Higher concentrations of added protein could yield higher immobilized protein densities on the particles. In contrast to EDC, the yields of protein immobilization via the a ctivation of cyanamide were relatively lower. Nanoparticles bound with avidin could attach a single-stranded DNA through the avidin-biotin interaction and hybridize with a DNA probe. The DNA hybridization was confirmed by fluorescence microscopy observations. Immobilized DNA on nanoparticles by this technique may have widespread applicability to the detection of specific nucleic acid sequence and targeting of DNA to particular cells.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.18 no.4
• /
• pp.85-105
• /
• 2005

Purpose : Investigate the effects of Chungganhaewooltang(CHT) on immobilization-stress or cold-stress in C576BL/6J mice. Methods : Male C57BL/6J 30 mice of weighting 18${\pm}$2g, were divided into sixs groups including the immobilization-stress group(5heads), after immobilization-stress CHT oral administration(500mg/kg) groups(5heads), cold-stress group(5heads) and after cold-stress CHT oral administration(500mg/kg) groups(5heads). then we observed changes in the serum histamine and corticosterone level and changes immune system Results : Immobilization-stress or cold-stress increased the serum level of histamine and corticosterone. CHT decreased the serum level of histamine and corticosterone increased by cold-stress. CHT inhibited the release of histamine from mast cells at the concentration of 0.1 mg/ml. In addition, immobilization-stress or cold-stress decreased the cell viability of murine thymocytes and splenocytes. CHT increased the cell viability of thymocytes decreased by immobilization-stress or cold-stress, but did not affect the cell viability of splenocytes decreased by immobilization-stress or cold-stress. Also immobilization-stress or cold-stress increased DNA fragmentation of thymocytes and splenocytes. CHT decreased DNA fragmentation of thymocytes increased by immobilization-stress or cold-stress, but did not affect DNA fragmentation of splenocytes increased by immobilization-stress or cold-stress. Immobilization-stress increased the population of thymic $CD4^+$ cells. CHT decreased the population of thymic $CD4^+$ cells increased by immobolization-stress. Immobilization-stress or cold-stress decreased the population of $B220^+$ cells and increased the population of $thy1^+$ cells. CHT decreased the population of $thy1^+$ cells increased by immobilization-stress or cold-stress. Immobilization-stress or cold-stress increased the population of splenic $CD4^+$ cells and $CD8^+$ cells. CHT decreased the population of splenic $CD4^+$ cells increased by immobolization-stress or cold-stress. Immobilization-stress or cold-stress decreased the production of ${\gamma}-interferon$(IFN) interleukin(IL)-2 and IL-4. CHT enhanced the production of ${\gamma}-IFN$ decreased by immobilization-stress or cold-stress but did not affect the production of IL-2 and IL-4 decreased by immobilization-stress or cold-stress. Furthermore, Immobilization- stress or cold-stress decreased the phagocytic activity of peritoneal macrophages and the production of nitric oxide. CHT enhanced the phagocytic activity and nitric oxide production decreased by cold-stress. Conclusion : CHT may be useful for the prevention and treatment of stress via suppression of serum histamine and corticosterone level and enhancement of immune response.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.3
• /
• pp.379-383
• /
• 2005

This research aims to develop DNA chip array without an indicator. We fabricated microelectrode array by photolithography technology. Several DNA probes were immobilized on an electrode. Then, indicator-free target DNA was hybridized by an electrical force and measured electrochemically. Cyclic-voltammograms (CVs) showed a difference between DNA probe and mismatched DNA in an anodic peak. Immobilization of probe DNA and hybridization of target DNA could be confirmed by fluorescent. This indicator-free DNA chip microarray resulted in the sequence-specific detection of the target DNA quantitatively ranging from $10^{-18}\;M\;to\;10^{-5}$ M in the buffer solution. This indicator-free DNA chip resulted in a sequence-specific detection of the target DNA.

• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.263-265
• /
• 2002

We have used the secondary-step immobilization methods based on the chip pattern of hydrophobic self-assembly layers to assemble microfabricated particles onto the chip pattern. Immobilization of DNA, fabrication of the particles and the chip pattern, arrangement of the particles on the chip pattern, and recognition of each using DNA fluorescence measurement were carried out. Establishing the walls, the arrangement stability of the particles was improved. Each DNA is able to distinguish by using the lithography process on the particles. Advantages of this method are process simplicity, wide applicability and stability. It is thought that this method can be applicable as a new fabrication technology to develop a minute integration type biosensor microarray.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.8
• /
• pp.365-370
• /
• 2003

This research aims to develop an indicator-free DNA chip using micro-fabrication technology. At first, we fabricated a DNA microarray by lithography technology. Several probe DNAs consisting of thiol group at their 5-end were immobilized on the gold electrodes. Then indicator-free target DNA was hybridized by an electrical force and measured electrochemically in potassium ferricyanide solution. Redox peak of cyclic-voltammogram showed a difference between target DNA and mismatched DNA in an anodic peak current. Therefore, it is able to detect various genes electrochemically after immobilization of various probe DNAs and hybridization of indicator-free DNA on the electrodes simultaneously It suggested that this DNA chip could recognize the sequence specific genes.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.11
• /
• pp.1667-1670
• /
• 2004

In DNA microarray produced by DNA-deposition technology, DNA-immobilization and -hybridization yields on a solid support are most important factors for its accuracy and sensitivity. We have developed a dendrimeric support using silylated aldehyde slides and polyamidoamine (PAMAM) dendrimers. An oligonucleotide array was prepared through a crosslinking between the dendrimeric support and an oligonucleotide. Both DNAimmobilization and -hybridization yields on the solid support increased by the modification with the dendrimers. The increase of the immobilization and hybridization efficiency seems to result from a threedimensional arrangement of the attached oligonucleotide. Therefore, our dendrimeric support may provide a simple and efficient solution to the preparation of DNA microarrays with high-density DNA-deposition and high hybridization efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.410-411
• /
• 2006

High throughput analysis using a DNA chip microarray is powerful tool in the post genome era. Less labor-intensive and lower cost-performance is required. Thus, this paper aims to develop the multi-channel type label-free DNA chip and detect SNP (Single nucleotide polymorphisms). At first, we fabricated a high integrated type DNA chip array by lithography technology. Various probe DNAs were immobilized on the microelectrode array. We succeeded to discriminate of DNA hybridization between target DNA and mismatched DNA on microarray after immobilization of a various probe DNA and hybridization of label-free target DNA on. the electrodes simultaneously. This method is based on redox of an electrochemical ligand.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.4
• /
• pp.410-414
• /
• 2004

High throughput analysis using a DNA chip microarray is powerful tool in the post genome era. Less labor-intensive and lower cost-performance is required. Thus, this paper aims to develop the multi-channel type label-free DNA chip and detect SNP (Single nucleotide polymorphisms). At first, we fabricated a high integrated type DNA chip array by lithography technology. Various probe DNAs were immobilized on the microelectrode array. We succeeded to discriminate of DNA hybridization between target DNA and mismatched DNA on microarray after immobilization of a various probe DNA and hybridization of label-free target DNA on the electrodes simultaneously. This method is based on redox of an electrochemical ligand.