• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.1
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• pp.87-92
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• 2004

This review focuses on the developed and the being developed environmental sensors in particular biological sensors. As well as discussing the classification and some main principles, presenting current trend of the environmental sensors is given. Two main categories are immunosensors and catalytic sensors. In addition to those. DNA or RNA sensors or protein based sensors are discussed. Some crucial examples of the applications of such sensors are given to show how the sensor technology it used for environmental and biological monitoring, biomarkers of exposure.

• Journal of Sensor Science and Technology
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• v.18 no.2
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• pp.160-167
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• 2009

In this study, secondary antibody-containing quartz crystal microbalance(QCM) sensor chip was prepared and utilized for the detection of human and bovine haptoglobin. Anti-goat immunoglobulin G antibody, which is a secondary antibody capable of capturing primary antibodies raised in goat, was immobilized through the reaction between hydrazide and aldehyde group prepared on the QCM surface and antibody respectively. The resulting sensor chip showed higher stability in the repeated surface regeneration with acidic dissociation solution as well as requiring lower amount of primary antibody when compared to the protein G sensor chip. The secondary antibody sensor chip was applied for the estimation of bovine and human haptoglobin.

• Journal of the Korean Vacuum Society
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• v.16 no.1
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• pp.52-57
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• 2007

The interaction force between biomolecules(DNA-DNA, antigen-antibody, ligand-receptor, protein-protein) defines not only biomolecular function, but also their mechanical properties and hence bio-sensor. Atomic force microscopy(AFM) is nowadays frequently applied to determine interaction forces between biological molecules and biomolecular force measurements, obtained for example using AFM can provide valuable molecular-level information on the interactions between biomolecules. A proper modification of an AFM tip and/or a substrate with biomolecules permits the direct measurement of intermolecular interactions, such as DNA-DNA, protein-protein, and ligand-receptor, etc. and a microcantilever-based sensor appeared as a promising approach for ultra sensitive detection of biomolecular interactions.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.4
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• pp.275-287
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• 2000

Fermentation strategies for recombinant protein production in Pichia pastoris have been investigated and are reviewed here. Characteristics of the expression system, such as phenotypes and carbon utilization, are summarized. Recently reported results such as growth model establishment, app58lication of a methanol sensor, optimization of substrate feeding strategy, DOstat controller design, mixed feed technology, and perfusion and continuous culture are discussed in detail.

• Journal of Sensor Science and Technology
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• v.20 no.4
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• pp.226-229
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• 2011

Label-free detection of biomolecular interactions was performed using BioFET(Biologically sensitive Field-Effect Transistor) and SPR(Surface Plasmon Resonance). Qualitative information on the immobilization of an anti-IgG and antibody-antigen interaction was gained using the SPR analysis system. The BioFET was used to explore the pI value of the protein and to monitor biomolecular interactions which caused an effective charge change at the gate surface resulting in a drain current change. The results show that the BioFET can be a useful monitoring tool for biomolecular interactions and is complimentary to the SPR system.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1717-1725
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• 2013

The objectives of this study were to compare visual observation and an electronic grazing time method and to evaluate the effects of nutritional plans on intake, grazing behavior and horizontal and vertical locomotion of young bulls in a tropical pasture. Thirty-nine Nellore young bulls with an average body weight of $345{\pm}9.3$ kg kept in pasture were used. The experimental treatments consisted of: restricted: animals kept in a plot with a low mass of forage receiving mineral mixture only; control: animals receiving mineral mixture only; HPHC: a high protein and high carbohydrate supplement; HPLC: a high protein and low carbohydrate supplement; LPHC: a low protein and high carbohydrate supplement; LPLC: a low protein and low carbohydrate supplement. GPS collars equipped with activity sensors were used. Information about head position, latitude, longitude and altitude were recorded. Daytime grazing behavioral patterns monitored by a continuous focal animal recording method was compared to behavior estimated by the activity sensor. Feed intake was estimated by a marker method. The Restricted group presented lower (p<0.05) intake of dry matter and TDN. However, difference in dry matter intake was not found (p>0.05) between non-supplemented and supplemented animals. Difference was not found (p>0.05) in daytime grazing time obtained by visual observation or the activity sensor method. The restricted group showed longer (p<0.05) grazing time (9.58 h/d) than other groups, but difference was not found (p>0.05) in the grazing time between Control (8.35 h/d) and supplemented animals (8.03 h/d). The Restricted group presented lower (p<0.05) horizontal locomotion distance (2,168 m/d) in comparison to other groups (2,580.6 m/d). It can be concluded that the use of activity sensor methods can be recommended due to their being similar to visual observation and able to record 24-h/d. While supplements with high carbohydrates reduce pasture intake, they do not change grazing behavior. Moderate supplementation (until 50% of protein requirement and 30% of energy requirement) of beef cattle on tropical pasture has no effect on daily locomotion.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.206-212
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• 1998

An improved antibody-coated sensor system based on quartz crystal microbalance was developed for the detection of Salmonella spp. An antibody against Salmonella common structural antigen was immobilized onto one gold electrode of the piezoelectric quartz crystal surface by various immobilization procedures. The best results in sensitivity and stability were obtained with the thin layers of protein A and 3,3'-dithiopropionimidate.2HCI(DTBP), a homobifunctional thiol-cleavable crosslinker. After the addition of a S. typhimurium suspension into a reaction cell with 0.1 M sodium phosphate buffer, pH 7.2, the resonant frequency owing to S. typhimurium adsorption decreased conspicuously. The antibody-immobilized crystals prepared by the gold-protein A complex formation and DTBP thiolation showed the frequency shifts of 80 and 283 Hz, respectively. The time required for maximum frequency shift was about 30~60 min. The antibody-coated crystal could be reused for 6~8 consecutive assays.

• Analytical Science and Technology
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• v.19 no.1
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• pp.9-17
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• 2006

The application and analysis of the interaction of various biomaterials including the concentration of biomaterials, thickness, and the ability of the detection of the analytical kinetic data of special biomaterials have been performed by SPR(surface plasmon resonance) sensor. To fabricate the scanning SPR, we designed data acquisition board and LabVIEW program for the personal computer to control the SPR sensor and collect the data from detector.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1593-1597
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• 2009

A biosensor has been developed based on induced wavelength shifts in the Fabry-Perot fringes in the visible reflection spectrum of appropriately derivatized thin films of porous silicon semiconductors. Porous silicon (PSi) was generated by an electrochemical etching of silicon wafer using two electrode configurations in aqueous ethanolic HF solution. Porous silicon displayed Fabry-Perot fringe patterns whose reflection maxima varied spatially across the porous silicon. The sensor system studied consisted of a mono layer of porous silicon modified with Protein A. The system was probed with various fragments of an aqueous Human Immunoglobin G (Ig G) analyte. The sensor operated by measurement of the Fabry-Perot fringes in the white light reflection spectrum from the porous silicon layer. Molecular binding was detected as a shift in wavelength of these fringes.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.1-6
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• 1999

A piezoelectric (PZ) biosensor system detecting Salmonella spp. was developed. The system consisted of an oscillator, a frequency counter and an antibody-immobilized quartz crystal. An anti-Salmonella antibody was immobilized on one gold. surface of the quartz crystal with protein A. Salmonella detection was made by measuring resonant frequency shift owing to a mass change by specific binding of microbial cells to the gold surface of the PZ crystal. The PZ antibody sensor was operated optimally at 0.1M phosphate buffer, pH 7.2 and $35^{\circ}C$. The sensor was quite specific to Salmonella spp. The obtained frequency shift was correlated with the Salmonella concentration in the range of $10^5{\sim}10^6\;CFU/mL$. The frequency shift increased further by addition of polystyrene beads. The Salmonella detection which is indicated by a steady-state microbial adsorption to the quartz crystal was accomplished within 50min.