Publications by authors named "Jang Ah Kim"

Article Synopsis
  • Plasmo-thermo-electrophoresis (PTEP) uses plasmonic microstructures to create convection currents and forces that enable the movement of particles in suspension, with potential applications in cell manipulation and targeted drug delivery.
  • The study aims to characterize the motion and swarming effects of various particles and bacterial cells, which could help design effective microrobots and drug delivery systems.
  • Results showed that PTEP can generate significant drag forces, and certain bacteria with negative zeta potential and smoother shapes displayed enhanced swarming behavior, aiding in predicting the behavior of similar particles.
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In this article, we demonstrate a plasmo-thermal bacterial accumulation effect using a miniature plasmonic optical fiber. The combined action of far-field convection and a near-field trapping force (referred to as thermophoresis)-induced by highly localized plasmonic heating-enabled the large-area accumulation of . The estimated thermophoretic trapping force agreed with previous reports, and we applied speckle imaging analysis to map the in-plane bacterial velocities over large areas.

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Graphene was chemically aminated via cycloaddition. Aziridine-ring linkages were formed by covalently modifying the C-C double bonds in graphene. The aminated graphene presents an enhanced hydrophilicity, the contact angle with water decreases from 80.

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Contact force monitoring technology during cardiac catheter ablation has become a major issue as both appropriate RF delivery and risk-free therapy have been more and more significant. In this study, an elastic waveguide was utilized to detect the contact force of 0 to 40 gF applied at the end of the sensor tip. The sensor showed a hysteresis between the force loading and releasing because of the elasticity of waveguide.

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Due to specific or as designed self-assembly, DNA nanostructures gaining popularity in various nanoscale electronic applications. Herein, a novel divalent metal ion-DNA complex known as M-DNA have been investigated for its photoelectric characteristics. The increased conductivity of M-DNA thin films is attributed to the metal ion electrical and optical properties.

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We present two free-solution annealed DNA nanostructures consisting of either cross-tile CT1 or CT2. The proposed nanostructures exhibit two distinct structural morphologies, with one-dimensional (1D) nanotubes for CT1 and 2D nanolattices for CT2. When we perform mica-assisted growth annealing with CT1, a dramatic dimensional change occurs where the 1D nanotubes transform into 2D nanolattices due to the presence of the substrate.

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We studied the physical characteristics of modified-DNA (M-DNA) double crossover crystals fabricated via substrate-assisted growth with various concentrations of four different divalent metallic ions, Cu(2+), Ni(2+), Zn(2+), and Co(2+). Atomic force microscopy (AFM) was used to test the stability of the M-DNA crystals with different metal ion concentrations. The AFM images show that M-DNA crystals formed without deformation at up to the critical concentrations of 6 mM of [Cu(2+)], 1.

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The electronic properties of biomolecules and their hybrids with inorganic materials can be utilized for the fabrication of nanoelectronic devices. Here, we report the charge transport behavior of protein-shelled inorganic nanoparticles combined with graphene and demonstrate their possible application as a bionanohybrid capacitor. The conductivity of PepA, a bacterial aminopeptidase used as a protein shell (PS), and the platinum nanoparticles (PtNPs) encapsulated by PepA was measured using a field effect transistor (FET) and a graphene-based FET (GFET).

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There is growing demand for the development of efficient ultrasensitive radiation detectors to monitor the doses administered to individuals during therapeutic nuclear medicine which is often based on radiopharmaceuticals, especially those involving beta emitters. Recently biological materials are used in sensors in the nanobio disciplines due to their abilities to detect specific target materials or sites. Artificially designed two-dimensional (2D) DNA lattices grown on a substrate were analyzed after exposure to pure beta emitters, (90)Sr-(90)Y.

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Our recent studies on metal-organic nanohybrids based on alkylated graphene oxide (GO), reduced alkylated graphene oxide (RGO) and InP/ZnS core/shell quantum dots (QDs) are presented. The GO alkylated by octadecylamine (ODA) and the QD bearing a dodecane thiol (DDT) ligand are soluble in toluene. The nanocomposite alkylated-GO-QD (GOQD) is readily formed from the solution mixture.

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The unexpected nuclear accidents have provided a challenge for scientists and engineers to develop sensitive detectors, especially for alpha radiation. Due to the high linear energy transfer value, sensors designed to detect such radiation require placement in close proximity to the radiation source. Here we report the morphological changes and optical responses of artificially designed DNA thin films in response to exposure to alpha radiation as observed by an atomic force microscope, a Raman and a reflectance spectroscopes.

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Graphene is a zero band-gap semi-metal with remarkable electromagnetic and mechanical characteristics. This study is the first ever attempt to use graphene in the surface plasmon resonance (SPR) sensor as replacement material for gold/silver. Graphene, comprised of a single atomic layer of carbon, is a purely two-dimensional material and it is an ideal candidate for use as a biosensor because of its high surface-to-volume ratio.

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