Publications by authors named "Byung-Keun Oh"

Hydrogen peroxide (HO) has been a fascinating target in various chemical, biological, clinical, and industrial fields. Several types of fluorescent protein-stabilized gold nanoclusters (protein-AuNCs) have been developed for sensitive and easy detection of HO. However, its low sensitivity makes is difficult to measure negligible concentrations of HO.

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The degeneration or loss of skeletal muscles, which can be caused by traumatic injury or disease, impacts most aspects of human activity. Among various techniques reported to regenerate skeletal muscle tissue, controlling the external cellular environment has been proven effective in guiding muscle differentiation. In this study, we report a nano-sized graphene oxide (sGO)-modified nanopillars on microgroove hybrid polymer array (NMPA) that effectively controls skeletal muscle cell differentiation.

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Microfluidic-based biosensors have been developed for their precise automatic reaction control. However, these biosensors require external devices that are difficult to transport and use. To overcome this disadvantage, our group made an easy-to-use, cheap, and light pumpless three-dimensional photo paper-based microfluidic analytical device (3D-μPAD; weight: 1.

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Noble metal nanomaterials, such as gold, silver, and platinum, have been studied extensively in broad scientific fields because of their unique properties, including superior conductivity, plasmonic property, and biocompatibility. Due to their unique properties, researchers have used them to fabricate biosensors. Recently, biosensors for detecting respiratory illness-inducing viruses have gained attention after the global outbreak of coronavirus disease (COVID-19).

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In this study, an electrochemical biosensor composed of a horseradish peroxidase (HRP)-encapsulated protein nanoparticles (HEPNP) was fabricated for the sensitive and selective detection of HO. The HEPNP has a three-dimensional structure that can contain a large amount of HRP; therefore, HEPNP can amplify the electrochemical signals necessary for the detection of HO. Furthermore, reduced graphene oxide (rGO) was used to increase the efficiency of electron transfer from the HEPNP to an electrode, which could enhance the electrochemical signal.

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Immuno-assay is one of diagnostic methods that usually measures biomarkers associated with cancers. However, this method is complex and take a long time to analyze. To overcome these disadvantages, many immuno-sensing chips have been designed and developed.

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Gold particles have been widely used in the treatment of prostate cancer due to their unique optical properties, such as their light-heat conversion in response to near-infrared radiation. Due to well-defined synthesis mechanisms and simple manufacturing methods, gold particles have been fabricated in various sizes and shapes. However, the low photothermal transduction efficiency in their present form is a major obstacle to practical and therapeutic uses of these particles.

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Many methods for early diagnosis of the disease use biomarker tests, which measure indicators of biological state in body fluids or blood. However, a limitation of these methods is their low sensitivity to biomarkers. In this study, human serum albumin (HSA) based nanoparticles capable of encapsulating excess horseradish peroxidase (HRP) are synthesized and applied to the development of enzyme-linked immunosorbent assay (ELISA) kit with ultra-high sensitivity.

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Biological production of 2,3-butanediol (2,3-BDO), a C4 platform chemical, has been studied recently, but the high cost of separation and purification before chemical conversion is substantial. To overcome this obstacle, we have conducted a study to convert 2,3-BDO to mevalonate, a terpenoid intermediate, using recombinant Pseudomonas putida and this biological process won't need the separation and purification process of 2,3-BDO. The production of mevalonate when 2,3-BDO was used as a substrate was 6.

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Nanoparticles (NPs) of protein-based materials have become one of the most promising candidates for drug carriers in drug-delivery systems because of their in vivo nontoxicity, biodegradability, compatibility with hydrophilic drugs, and adaptability to the human body. Many studies have investigated the fabrication of protein NPs from human serum albumin (HSA) as a new drug carrier. It is important for these NPs to remain in the blood until they reach their therapeutic target to achieve the desired effect; the quicker the clearance of drugs from the body, the shorter is the residence time of drugs in the body, which eventually reduces drug efficacy.

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Magnetic cobalt ferrite/silica nanoparticles (MSNs) and methyl functionalized MSNs (methyl-MSNs) were used to enhance lipid production in Chlorella vulgaris culture through enhancement of gas-water mass transfer and increased dissolved concentration of CO . Methyl-MSNs enhanced CO -water mass transfer rate better than MSNs, and 0.3 wt% methyl-MSNs are more effective than 0.

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A novel and simple method for the fabrication of gold nanoparticle (AuNP) clusters was introduced for use as an efficient near-infrared (NIR) photothermal agent. Cationic surfactants were employed to assemble AuNPs into clusters, during which polyvinylpyrrolidone (PVP) was used to stabilize the AuNP clusters. Through this manner, AuNP clusters with a uniform shape and a narrow size distribution (55.

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In this study, we report the production of uracil from methanol by an isolated methylotrophic bacterium, Methylobacterium sp. WJ4. The use of methanol as alternative carbon feedstock is attractive option in biotechnology.

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Since the delivery kinetics of different cell types are different, the signal from the target cell is greatly affected by the noise signal of the diagnostic system. This is a major obstacle hindering the practical application of intracellular diagnostic systems, such as tumor heterogeneity. To address these issues, here we present a microRNA detection platform using fluorescence-encoded nanostructured DNA-based probes.

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In this research, the electrochemical biosensor composed of myoglobin (Mb) on molybdenum disulfide nanoparticles (MoS NP) encapsulated with graphene oxide (GO) was fabricated for the detection of hydrogen peroxide (HO). Hybrid structure composed of MoS NP and GO (GO@MoS) was fabricated for the first time to enhance the electrochemical signal of the biosensor. As a sensing material, Mb was introduced to fabricate the biosensor for HO detection.

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Methane is an abundant, inexpensive one-carbon feedstock and one of the most powerful greenhouse gases. Because it does not compete with food demand, it is considered a promising carbon feedstock for the production of valuable products using methanotrophic bacteria. Here, we isolated a novel methanotrophic bacterium, Methylomonas sp.

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Dopamine (DA) is one kind of neurotransmitter in central nervous system which is indicator of neural disease. For this reason, determination of DA concentration in central nervous system is very important for early diagnosis of neural disease. In this study, we designed micro electrode array and fabricated by MEMS technology.

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We investigated the cellular uptake efficiencies of differently-sized silica nanoparticles in the presence and the absence of trans-activator of transcription (TAT) peptide. Silica nanoparticles incorporating fluorescent dye molecules with diameters of 30 to 800 nm were synthesized, and the surfaces of the silica nanoparticles were functionalized with TAT peptides or 3-aminopropyltriethoxysilane (APTES). Confocal microscopy and flow cytometry were used to determine the cellular locations and the uptake efficiencies of positively-charged silica nanoparticles (APTES- and TAT-) of various sizes from 30 to 800 nm.

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Accurate cancer diagnosis often requires extraction and purification of genetic materials from cells, and sophisticated instrumentations that follow. Otherwise in order to directly treat the diagnostic materials to cells, multiple steps to optimize dose concentration and treatment time are necessary due to diversity in cellular behaviors. These processes may offer high precision but hinder fast analysis of cancer, especially in clinical situations that need rapid detection and characterization of cancer.

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Article Synopsis
  • - A novel immunosensor using scanning tunneling microscopy (STM) was created to detect the HIV-1 virus using gold nanoparticles and fragmented antibodies pre-attached to a gold surface.
  • - The sensor employs a "sandwich assay" approach, where HIV-1 virus-like particles (HIV-1 VLPs) are combined with the gold nanoparticle and antibody complex for detection.
  • - The effectiveness of this method was confirmed through current mapping profiles, revealing that it can accurately detect viral particles and potentially be adapted for other living materials.
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The purpose of this study was to investigate the potential of zeolite-supported sulfatereducing bacteria (SRB) in enhancing the removal of Cu(2+), Ni(2+), and Cr(6+) in contaminated seawater. Our results show that SRB-immobilized zeolite carriers can enhance the removal of heavy metals. In addition, heavy metals were generally better removed at conditions of 37°C.

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In this study, we demonstrated a simple, rapid and inexpensive fabrication method to develop a novel gold nanobouquet structure fabricated indium tin oxide (GNB/ITO) electrode based on electrochemical deposition of gold ions onto ITO substrate. The morphology of the fabricated electrode surface was characterized by scanning electron microscopy (SEM) to confirm the GNB formation. Enzyme-free detection of glucose using a GNB/ITO electrode was described with high sensitivity and selectivity based on cyclic voltammetry assay.

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Localized surface plasmon resonance (LSPR) is the phenomenon that is observed on specific metal nanoparticles (NPs) like Au, Ag which can be used for sensitive detection for many kinds of biomaterials. Dopamine (DA) is a typical neurotransmitter considered as indicator of some neural diseases. Due to its small size, it is very difficult to detect DA at low concentrations directly and sensitively with conventional sensing techniques.

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Therapeutic nanocomplexes have been extensively developed for the effective treatment of aggressive cancers because of their outstanding versatility, easy manipulation, and low cytotoxicity. In this study, we describe the synthesis of a novel bovine serum albumin (BSA)-based nanocomplex harboring both Bcl-2-specific small interfering RNA (siRNA) and gold (Au) nanorods (siRNA and rods encapsulated in BSA; SREB) with the aim of developing a targeted breast cancer therapeutic. The SREB complexes contained 2 × 10(5) siRNA molecules and eight Au nanorods per BSA complex and were successively functionalized with polyethylene glycol (PEG) and anti-ErbB-2 antibodies to facilitate active targeting.

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Development of a sensitive and selective detection system for pathogenic viral agents is essential for medical healthcare from diagnostics to therapeutics. However, conventional detection systems are time consuming, resource-intensive and tedious to perform. Hence, the demand for sensitive and selective detection system for virus are highly increasing.

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