• Title/Summary/Keyword: Nanosensor

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Classification of Measurement Methods of Surface Plasmon Resonance Biosensors by SK Index (SK 지수를 이용한 표면 플라즈몬 공명 바이오 센서의 측정방법의 분류)

  • Lee, Seung-Ki
    • Journal of Sensor Science and Technology
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    • v.13 no.5
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    • pp.342-349
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    • 2004
  • SK (SPR Kinds) index, which can categorize the complicated measurement methods of surface plasmon resonance by simple method, has been proposed and verified. SK index is composed of three digits, where each digit presents the type of immobilized ligand, the type of illumination and the kinds of varying parameter, sequentially. The measurement method of (33#) series among SK indices shows the possibility of the multi-sensing capability, by which the response of 2-dimensional array of immobilized ligands can be detected simultaneously. The proposed possibility of multi-sensing capability has been verified by the modeling that is based on Fresnel reflection model.

A novel surface plasmon resonance sensor without using imaging devices (영상 소자를 사용하지 않는 새로운 표면 플라즈몬 공명 센서)

  • Lee, Seung-Ki
    • Journal of Sensor Science and Technology
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    • v.15 no.5
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    • pp.347-351
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    • 2006
  • A novel surface plasmon resonance sensor, which can measure 2-dimensional array of immobilized ligands without using imaging devices such as CCD, has been proposed. Regular surface plasmon resonance can be directly used due to the insertion of additional layers with different thickness, on which each ligands are immobilized. Surface plasmon resonance signals are separated depending on the thickness of additional layers. The possibility of multi-sensing capability of the proposed surface plasmon resonance sensor has been verified by the modeling that is based on Fresnel reflection model.

Detection of Molecules using the Nanoparticle Arrays (나노입자 배열을 이용한 분자 검출)

  • Ha, Dong-Han;Kim, Sang-Hun;Yun, Yong-Ju;Park, Hyung-Ju;Yun, Wan-Soo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1617-1622
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    • 2008
  • We report a new molecular detection process which measures the changes in the plasmon resonance peaks of periodic Au nanoparticle arrays fabricated using the electron beam lithography. As the Au nanoparticle arrays are modified by the chemical reaction in solutions having various concentrations of a target molecule, both the position and intensity of the plasmon peak change in proportion to the concentration of the target molecule. We expect that the process developed in this work can be employed for fine tuning of the plasmon peak wavelength and also for the optical detection of various kinds of molecules. Moreover, this method may improve the measurement accuracy compared with existing approaches that use only one change (peak wavelength or peak intensity) as a readout value for the molecular detection.

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The Current Status and Future Outlook of Quantum Dot-Based Biosensors for Plant Virus Detection

  • Hong, Sungyeap;Lee, Cheolho
    • The Plant Pathology Journal
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    • v.34 no.2
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    • pp.85-92
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    • 2018
  • Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), widely used for the detection of plant viruses, are not easily performed, resulting in a demand for an innovative and more efficient diagnostic method. This paper summarizes the characteristics and research trends of biosensors focusing on the physicochemical properties of both interface elements and bioconjugates. In particular, the topological and photophysical properties of quantum dots (QDs) are discussed, along with QD-based biosensors and their practical applications. The QD-based Fluorescence Resonance Energy Transfer (FRET) genosensor, most widely used in the biomolecule detection fields, and QD-based nanosensor for Rev-RRE interaction assay are presented as examples. In recent years, QD-based biosensors have emerged as a new class of sensor and are expected to open opportunities in plant virus detection, but as yet there have been very few practical applications (Table 3). In this article, the details of those cases and their significance for the future of plant virus detection will be discussed.

Selection of Peptides Binding to HCV E2 and Inhibiting Viral Infectivity

  • Hong, Hye-Won;Lee, Seong-Wook;Myung, Hee-Joon
    • Journal of Microbiology and Biotechnology
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    • v.20 no.12
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    • pp.1769-1771
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    • 2010
  • The envelope glycoprotein E2 of hepatitis C virus (HCV) binds to various cell surface receptors for viral infection. We performed biopanning against this protein and selected peptides from phage display peptide libraries. Two short peptides, pep7-1 and pep12-1, were selected and their ability to inhibit the infection process was investigated. When pep7-1 was present, the infectivity of HCV particles in cell culture was notably decreased. This decrease was demonstrated by Western blot analysis, immunofluorescence assay, and reverse transcription PCR assay. However, pep12-1 showed little inhibitory effect on HCV infection.

Magneto-optical Measurements of Semiconductor Quantum Structures in Pulsed-magnetic Fields

  • Kim, Yongmin
    • Applied Science and Convergence Technology
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    • v.23 no.1
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    • pp.1-13
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    • 2014
  • Semiconductor quantum structures are often characterized by their energy gaps which are modified by the quantum size effect. Energy levels in semiconductors can be realized by optical transitions within confined structures. Photoluminescence spectroscopy in magnetic fields at low temperatures has proved to be a powerful technique for investigating the electronic states of quantum semiconductor heterostructures and offers a complimentary tool to electrical transport studies. In this review, we examine comprehensive investigations of magneto-excitonic and Landau transitions in a large variety of undoped and doped quantum-well structures. Strong magnetic fields change the diamagnetic energy shift of free excitons from quadratic to linear in B in undoped single quantum well samples. Two-dimensional electron gas induced by modulation doping shows pronounce quantum oscillations in integer quantum Hall regime and discontinuous transition at ${\nu}=1$. Such discontinuous transition can be explained as the formation of spin waves or Skyrmions.

Atomistic analysis of nano/micro biosensors

  • Chen, James;Lee, James D.
    • Interaction and multiscale mechanics
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    • v.3 no.2
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    • pp.111-121
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    • 2010
  • Dynamic analysis of nano/micro bio-sensors based on a multiscale atomistic/continuum theory is introduced. We use a generalized atomistic finite element method (GAFEM) to analyze a bio-sensor which has $3{\times}N_a{\times}N_p$ degrees of freedom, where $N_p$ is the number of representative unit cells and $N_a$ is the number of atoms per unit cell. The stiffness matrix is derived from interatomic potential between pairs of atoms. This work contains two studies: (1) the resonance analysis of nano bio-sensors with different amount of target analyte and (2) the dependence of resonance frequency on finite element mesh. We also examine the Courant-Friedrichs-Lewy (CFL) condition based on the highest resonance frequency. The CFL condition is the criterion for the time step used in the dynamic analysis by GAFEM. Our studies can be utilized to predict the performance of micro/nano bio-sensors from atomistic perspective.

Evaluation of combat calorie consumption based on GoBe2 nanosensor

  • Shuo Guan;Benxu Zou
    • Advances in nano research
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    • v.14 no.6
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    • pp.527-539
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    • 2023
  • Measuring energy burn during intensive combat sport has been a challenging concerns for a long time. In the present article, the energy consumption during combat sports is measured by use of wearable GoBe2 equipped with nanotechnology measuring devices. In this regard, 12 professional combat athletes were asked to wear GoBe2 devices during different sessions of intensive combat exercises. The curves provided by GoBe2 nano-sensor devices are further collected and analyzed for different combat durations. On the other hand, energy consumption in these athlete is calculated using other validated methods to evaluate reliability of GoBe2 wearable devices. Based on the results obtained from these experiments a multi-parameter mathematical model is presented for estimation of combat calorie consumptions. The results show that nanotechnology in these type of sensors could help in estimation of calorie consumption during combat. Moreover, the reliability of using wearable GoBe2 sensors are satisfactory except for some specific conditions. The mathematical model provides a satisfactory results based on athlete physical condition and also duration of the combat with about 8% error margin in the results.

Temperature-Dependent Mn Substitution Effect on LiNiO2

  • Seungjae Jeon;Sk. Khaja Hussain;Jin Ho Bang
    • Journal of Electrochemical Science and Technology
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    • v.15 no.1
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    • pp.161-167
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    • 2024
  • Despite the important role of manganese (Mn) in cobalt-free, Ni-rich cathode materials, existing reports on the effects of Mn as a substitute for cobalt are not consistent. In this work, we analyzed the performance of cathodes comprised of Li(Ni1-xMnx)O2 (LNMO). Both beneficial and detrimental results occurred as a result of the Mn substitution. We found that a complex interplay of effects (Li/Ni mixing driven by magnetic frustration, grain growth suppression, and retarded lithium insertion/extraction kinetics) influenced the performance and was intimately related to calcination temperature. This indicates the importance of establishing an optimal reaction temperature for the development of high-performance LNMO.

A Set of Anthocyanin Biosynthetic Genes are Differentially Expressed in Strawberry (Fragaria x ananassa cv Maehyang) during the Fruit Development Process (매향 딸기로부터 anthocyanin 합성 유전자의 분리 및 과실발달 과정에서의 발현 분석)

  • Bae, Ki-Suk;Kih, Joon-Yeong;Pyee, Jae-Ho
    • Journal of Life Science
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    • v.18 no.2
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    • pp.234-240
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    • 2008
  • Anthocyanin synthesis in strawberry (Fragaria x ananassa cv Maehyang) begins approximately 26 days postflowering and continued throughout fruit ripening. A set of cDNA clones encoding the anthocyanin biosynthetic enzymes were isolated from strawberry. A pair of primers were designed for polymerase chain reaction (PCR) through the comparison of the nucleotide sequences of homologous genes from diverse plants. Reverse transcriptase-PCRs were performed using cDNA synthesized from ripe fruit total RNA and the primers corresponding to each gene. Eight genes of the anthocyanin pathway were cloned and confirmed by sequencing to code for phenylalanine ammonia lyase (PAL), 4-cummarate CoA ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidine synthase (ANS), UDP-glucose:flavonoid-3-O-glucosyl-transferase (UFGT). Northern analyses showed that the corresponding genes were differentially expressed during the fruit development process. All genes except PAL were predominantly expressed in fruit. Expression of PAL, DFR and ANS was detected 10 days postflowering at the early stage of fruit development, declined for a while and sharply increased 22 days postflowering then showed a peak 34 days postflowering. The other genes, however, were not expressed up to 22 or 30 days postflowering when the initial fruit ripening events occur at the time of initiation of anthocyanin accumulation. The onset of anthocyanin synthesis in ripening strawberry coincides with a coordinated induction of the anthocyanin pathway genes, suggesting the involvement of regulatory genes. We propose that at least two different regulatory mechanisms playa role in the biosynthesis of anthocyanin during color development of strawberry.