Browsing by Author "Hu, Po-Sheng"

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Bio-inorganic nanocomposites of lysozyme amyloid fibrils and magnetic nanoparticles of different shape anisotropy
(2020-05-15)
Lackova, Veronika
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Tomasovicova, Natalia
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Olejniczak, Andrzej
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Zakutanska, Katarina
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Majorosova, Jozefina
The present study describes the interaction of an assorted shape of magnetic nanoparticles with lysozyme amyloid fibrils by atomic force microscopy and magnetization measurements. Mixture stability was verified by settling behaviour of NPs dispersions. A fibril solution doped with spherically shaped magnetic nanoparticles reveals the effect of particles' adsorption on the amyloid fibrils' surface. However, when spindle-like magnetic nanoparticles were doped, it led to zero interaction activity, which confesses subtle difference in fibrillary interaction with spherical particle that can be explained by diverse size of nanoparticles. Moreover, spherical MNPs showed excellent stability in sLAF, the spindle MNPs were unstable and exhibited limited dispersion.
Cs0.33WO3 compound nanomaterial-incorporated thin film enhances output of thermoelectric conversion in ambient temperature environment
(2018-06-01)
Cheng, Chih-Yi
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Chen, Guan-Lin
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Hu, Po-Sheng
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光電系統研究所
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照明與能源光電研究所
Cs0.33WO3 nanomaterial absorbs a range of near-infrared (NIR) wavelength spanning 900-2400 nm, of which the main contributor of heat energy may be utilized for electrical generation. In this research, the capability of Cs0.33WO3 nanomaterial in enhancing the output of a thermoelectric (TE) device by trapping the absorbed heat at the hot-side surface of the device is investigated. The material is synthesized through a combination of the processes of co-precipitation and wet nano-grinding, and the characterization of its structural and optical properties was carried out using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and visible-near-infrared absorption spectroscopy. Likewise, the photothermal property of Cs0.33WO3 nanomaterial, in the form of solution or solid film, is assessed to gain better insight into its effects on the electrical output of the TE device, utilizing a laser with wavelength of 808 nm, a solar simulator, and sunlight in ambient environment. Moreover, the photoelectric property of the Cs0.33WO3 nanomaterial-incorporated TE device was evaluated in four different types of weather condition, sunny, sunny with partly cloudy, cloudy, and rainy; and our results indicate that Cs0.33WO3 nanomaterial is capable of enhancing the output of thermoelectric conversion in an ambient environment. In a complete sunny day, when compared with a bare thermoelectric device, the coating of Cs0.33WO3 nanomaterial with concentration of 0.66 wt% demonstrated a rise of 13.1% in the maximal attainable temperature and a corresponding increase of 291% in maximal output voltage.
Dual Size-Dependent Effect of Fe3O4 Magnetic Nanoparticles Upon Interaction with Lysozyme Amyloid Fibrils: Disintegration and Adsorption
(2019-01-01)
Tomasovicova, Natalia
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Hu, Po-Sheng
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Zeng, Cyun-Lun
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Majorosova, Jozefina
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Zakutanska, Katatina
Nanomedicine compounds containing nanoparticles, such as iron oxides and gold, have been demonstrated to be effective in promoting different magnitudes of interaction with amyloid beta fibrils, of which disintegrating or inhibiting effects are of great importance to treating fibrillary aggregation-induced neurological disorders such as Alzheimer's disease. This research herein studies the interaction between lysozyme amyloid fibrils, a type of fibers derived from hen egg white lysozyme, and Fe3O4 magnetic nanoparticles (MNPs) of an assorted diameter sizes of 5 nm, 10 nm and 20 nm, using atomic force microscopy (AFM). Specifically, the effects of the sizes of negatively charged MNPs on the resultant amyloid fibrillary mixture was investigated. Our results of AFM images indicated that the interaction between MNPs and the fibrils commences immediately after adding MNPs to the fibril solution, and the actions of such MNPs-doped fibrillary interplay, either integration or segmentation, is strongly dependent on the size and volume concentration of MNPs. In the cases of 5 nm and 20 nm particles of equivalent volume concentration, the adsorption and agglomeration of MNPs onto the fibrillary surfaces was observed, whereas, interestingly, MNPs with diameter size of 10 nm enables segmentation of the slender fibrils into debris when a proper implemented volume concentration was found, which signifies utter destruction of the amyloid fibrillary structure.
Dynamic morphogenesis of dendritic structures formation in hen egg white lysozyme fibrils doped with magnetic nanoparticles
(2018-01-01)
Tomasovicova, Natalia
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Hu, Po-Sheng
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Zeng, Cyun-Lun
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Hurakova, Maria
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Csach, Kornel
In this research, the dynamic process of aggregation that forms microflower morphology in solution of lysozyme amyloid fibrils doped with spherical or spindle-like magnetic nanoparticles during the process of drying as well as their final microstructures were investigated. The prepared lysozyme amyloid fibrils as well as their mixtures with in-lab synthesized magnetic particles, which were prepared by adding the nanoparticles to the fibrils solution after the process of fibrillation was done, were characterized using brightfield trans-illumination-mode optical microscope, atomic force microscopy (AFM) and scanning electron microscope (SEM). Brightfield optical imaging bases upon photoabsorptive property of the fibrils-nanoparticle composites clearly reveals the morphological features in microscale, and additionally, for the in vivo, live action of the time-dependent process of self-assembly of such composites composed of fibrillary structure incorporated with magnetic particles was optically elucidated at ambient temperature. Moreover, while results of AFM reveal delicate and peculiar association of fibrils with magnetic nanoparticles of different shapes, SEM images illustrate a stark difference in fine detailed final morphology of microstructures associated with spherical and spindle-like nanoparticles. Our results indicated that the interaction between fibrils solution and the nanoparticles commence right after mixing, the dynamic process of forming dendritic structure resembling microflower morphology is on the order of minutes, and its final structure is highly dependent on the shape of magnetic nanoparticles. (C) 2017 Elsevier B.V. All rights reserved.
Effect of the concentration of protein and nanoparticles on the structure of biohybrid nanocomposites
(1970-01-01)
Majorosova, Jozefina
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Schroer, Martin A.
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Tomasovicova, Natalia
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Batkova, Marianna
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Hu, Po-Sheng
We present colloidal nanocomposites formed by incorporating magnetite Fe3O4 nanoparticles (MNPs) with lysozyme amyloid fibrils (LAFs). Preparation of two types of solutions, with and without addition of salt, was carried out to elucidate the structure of MNPs-incorporated fibrillary nanocomposites and to study the effect of the presence of salt on the stability of the nanocomposites. The structural morphology of the LAFs and their interaction with MNPs were analyzed by atomic force microscopy and small-angle x-ray scattering measurements. The results indicate that conformational properties of the fibrils are dependent on the concentration of protein, and the precise ratio of the concentration of the protein and MNPs is crucially important for the stability of the fibrillary nanocomposites. Our results confirm that despite the change in fibrillary morphology induced by the varying concentration of the protein, the adsorption of MNPs on the surface of LAF is morphologically independent. Moreover, most importantly, the samples containing salt have excellent stability for up to 1 year of shelf-life.
Hyperthermia Induced by Near-Infrared Laser-Irradiated CsWO3 Nanoparticles Disintegrates Preformed Lysozyme Amyloid Fibrils
(2020-03-01)
Hu, Po-Sheng
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Tomasovicova, Natalia
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Chou, Hsiu-Jen
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Li, Meng-Chang
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Vojtko, Marek
This research study attempts to prove the concept of the applicability of hyperthermia to treating the lysozyme amyloid fibrils (LAFs)'s self-assembled fibrillary aggregates by a feedback-modulated temperature controller ranging from 26 degrees C to 80 degrees C, and separately, by near-infrared (NIR) laser-irradiated cesium tungstate (CsWO3) nanoparticle (NPs). The dependence of the final morphology of the amyloidal assembly on external heating and the photothermal effect of the NPs on treating the fibrillary assembly were investigated and analyzed. Experimentally, atomic force microscopy (AFM), optical stereoscopy, and scanning electron microscopy (SEM) were used primarily to ensure mutual interaction between LAFs and NPs, optically elucidate the surface contour and final fibrillary assembly upon the influence of thermal treatment, and further reveal fine-details of the optical samples. Finally, conclusive remarks are drawn that the fibrillary structures doped with the NPs exhibit an increasing degree of unique orthogonality. As the temperature rises, utter deformation of the dendritic structures of fibrillary assemblies at 70 degrees C was found, and NIR laser-irradiated CsWO3 NPs have been demonstrated to be useful in topically destructing pre-assembled LAFs, which may be conducive to the future development of neurodegenerative therapeutic techniques.
Near -infrared optical reflectance microspectroscopy examining atrioventricular valvular rhythm of wildtype larval zebrafish as a pre -stage cardiac drug toxicity assay
(2020-06-01)
Hsieh, Hao-Chun
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Chang, Wei-Ting
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Hu, Po-Sheng
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光電系統研究所
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影像與生醫光電研究所
Tuning visible-wavelength spectrum of white-light super-continuum via etalon transmission in lamellar ZnO micro/nanoparticle-stacked structures
(2019-10-01)
Hu, Po-Sheng
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Chen, Guan-Lin
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Wu, Cheng-En
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光電系統研究所
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影像與生醫光電研究所
Multi-layered micro/nanostructures enable the fine-tuning of spectral bandwidth induced by coherent interference of multi-scattering and refraction bounded by a motive of Fabry Perot etalon. In this paper a ZnO micro/nanostructured thin film device is grown on a 21 nm silver film-sputtered sapphire substrates (0001) and attempted to be complied as a transmission-mode white-light spectrum tuning device. In details, the growth of the structures as a function of temporal duration and the effects of deposition of a 21 nm silver film atop sapphire substrates to the structural and optical properties of ZnO structures are investigated. Results of SEM imaging reveals that the insertion of the silver film enables synthesis of round ZnO particles at micro or nanoscales depending on the duration of growth time as opposed to the floral pattern associated with plain sapphire substrates. Characterizing material crystallization by XRD spectra found one dominant and two minor peaks along the planes of crystallization (002), and (100) and (101), correspondingly. Also, the characteristic PL peak at 380 nm was confirmed when excited at 325 nm, and the intensity decreases as the duration of growth time increases. Finally, growth duration-dependent modulation of peak wavelength and spectral bandwidth of the continuum laser was demonstrated.
Zno Micro/Nanostructures Grown on Sapphire Substrates Using Low-Temperature Vapor-Trapped Thermal Chemical Vapor Deposition: Structural and Optical Properties
(2018-01-01)
Hu, Po-Sheng
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Wu, Cheng-En
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Chen, Guan-Lin
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光電系統研究所
;
影像與生醫光電研究所
In this research, the Zn(C5H7O2)(2)center dot xH(2)O-based growth of ZnO micro/nanostructures in a low temperature, vapor-trapped chemical vapor deposition system was attempted to optimize structural and optical properties for potential biomedical applications. By trapping in-flow gas molecules and Zinc vapor inside a chamber tube by partially obstructing a chamber outlet, a high pressure condition can be achieved, and this experimental setup has the advantages of ease of synthesis, being a low temperature process, and cost effectiveness. Empirically, the growth process proceeded under a chamber condition of an atmospheric pressure of 730 torr, a controlled volume flow rate of input gas, N-2/O-2, of 500/500 Standard Cubic Centimeters per Minute (SCCM), and a designated oven temperature of 500 degrees C. Specifically, the dependence of structural and optical properties of the structures on growth duration and spatially dependent temperature were investigated utilizing scanning electron microscopy, X-ray diffraction (XRD), photoluminescence (PL), and ultraviolet-visible transmission spectroscopy. The experimental results indicate that the grown thin film observed with hexagonal structures and higher structural uniformity enables more prominent structural and optical signatures. XRD spectra present the dominant peaks along crystal planes of (002) and (101) as the main direction of crystallization. In addition, while the structures excited with laser wavelength of 325 nm emit a signature radiation around 380 nm, an ultraviolet lamp with a wavelength of 254 nm revealed distinctive photoluminescence peaks at 363.96 nm and 403.52 nm, elucidating different degrees of structural correlation as functions of growth duration and the spatial gradient of temperature. Transmittance spectra of the structures illustrate typical variation in the wavelength range of 200 nm to 400 nm, and its structural correlation is less significant when compared with PL.