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Z. Mitróová

Bio: Z. Mitróová is an academic researcher from Slovak Academy of Sciences. The author has contributed to research in topics: Liquid crystal & Carbon nanotube. The author has an hindex of 11, co-authored 38 publications receiving 405 citations.

Papers
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TL;DR: The response in capacitance to low external magnetic fields of suspensions of spherical magnetic nanoparticles, single-wall carbon nanotubes, and SWCNT functionalized with Fe(3)O(4) nanoparticles in a nematic liquid crystal has been studied experimentally.
Abstract: The response in capacitance to low external magnetic fields (up to 0.1 T) of suspensions of spherical magnetic nanoparticles, single-wall carbon nanotubes (SWCNT), SWCNT functionalized with carboxyl group (SWCNT-COOH), and SWCNT functionalized with Fe${}_{3}$O${}_{4}$ nanoparticles in a nematic liquid crystal has been studied experimentally. The volume concentration of nanoparticles was ${\ensuremath{\phi}}_{1}={10}^{\ensuremath{-}4}$ and ${\ensuremath{\phi}}_{2}={10}^{\ensuremath{-}3}$. Independent of the type and the volume concentration of the nanoparticles, a linear response to low magnetic fields (far below the magnetic Fr\'eederiksz transition threshold) has been observed, which is not present in the undoped nematic.

50 citations

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TL;DR: In this article, mesoporous silica particles were synthesized by sol-gel method from tetraethoxysilane (tetraethylorthosilicate, TEOS) and methyltriethioxysilanes (MTES), in ethanol and water mixture, at different ratios of the of the silica precursors.

40 citations

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TL;DR: Magnetically induced optical birefringence (Δ n ) was measured for magnetoferritin (MFer), horse spleen ferritin, and nanoscale magnetite aqueous suspensions as mentioned in this paper.

33 citations

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TL;DR: In this paper, the results of magnetization and AC susceptibility measurements performed on ferrimagnetic Mn32+[CrIII(CN)6]2·12H2O and ferromagnetic Ni3[Cr6] 2·12 H2O systems under pressure up to 0.9 GPa in a commercial SQUID magnetometer were presented.
Abstract: We present the results of magnetization and AC susceptibility measurements performed on ferrimagnetic Mn32+[CrIII(CN)6]2·12H2O and ferromagnetic Ni32+[CrIII(CN)6]2·12H2O systems under pressures up to 0.9 GPa in a commercial SQUID magnetometer. The magnetization process is affected by pressure: magnetization saturates at higher magnetic field, saturated magnetization μs of Ni3[Cr(CN)6]2 is reduced and almost unaffected for Mn3[Cr(CN)6]2 at low temperatures. The Curie temperature TC of Mn3[Cr(CN)6]2 increases with the applied pressure, ΔTC/Δp = 25.5 K GPa−1, due to a strengthened super-exchange antiferromagnetic interaction JAF, but it is not affected significantly in the case of Ni3[Cr(CN)6]2 with a dominant ferromagnetic JF super-exchange interaction. The increase in the JAF interaction is attributed to the enhanced value of the single electron overlapping integral S and the energy gap Δ of the mixed molecular orbitals t2g (Mn2+) and t2g (CrIII) induced by pressure.

31 citations

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TL;DR: In this article, the peroxidase-like activity of magnetorritin was investigated in the determination of hydrogen peroxide in the 5.8 to 88.2 mM concentration range.
Abstract: Magnetoferritin is a spherical biomacromolecule with a diameter of about 12 nm. It consists of a protein shell composed of apoferritin that is surrounding magnetic nanoparticles of magnetite (Fe3O4) or maghemite (γ-Fe2O3). Magnetoferritins with various iron content (loading factor) were synthetically prepared and their peroxidase-like activities studied via the oxidation of the chromogenic substrate N,N-diethyl-p-phenylenediamine sulfate by hydrogen peroxide to give a purple product with an absorption maximum at 551 nm. Magnetoferritin with higher loading factor exhibits a higher peroxidase-like activity. The catalytic activity was successfully applied to the determination of hydrogen peroxide in the 5.8 to 88.2 mM concentration range.

31 citations


Cited by
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TL;DR: This review discusses various nanomaterials that have been explored to mimic different kinds of enzymes and covers their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal.
Abstract: Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

2,951 citations

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TL;DR: This review will introduce the enzymatic features of iron oxide nanozyme (IONzyme), and summarize its novel applications in biomedicine.
Abstract: Iron oxide nanoparticles have been widely used in many important fields due to their excellent nanoscale physical properties, such as magnetism/superparamagnetism. They are usually assumed to be biologically inert in biomedical applications. However, iron oxide nanoparticles were recently found to also possess intrinsic enzyme-like activities, and are now regarded as novel enzyme mimetics. A special term, "Nanozyme", has thus been coined to highlight the intrinsic enzymatic properties of such nanomaterials. Since then, iron oxide nanoparticles have been used as nanozymes to facilitate biomedical applications. In this review, we will introduce the enzymatic features of iron oxide nanozyme (IONzyme), and summarize its novel applications in biomedicine.

377 citations

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TL;DR: This paper presents a meta-analyses of the chiral stationary phase of the response of the immune system to various types of materials and shows clear patterns of decline in the immune systems of mice treated with these materials.
Abstract: Günther Jutz,†,§ Patrick van Rijn,†,‡,§ Barbara Santos Miranda,‡ and Alexander Böker*,† †DWI Leibniz-Institut für Interaktive Materialien e.V., Lehrstuhl für Makromolekulare Materialien und Oberflac̈hen, RWTH Aachen University, Forckenbeckstrasse 50, D-52056 Aachen, Germany ‡Department of Biomedical Engineering-FB40, W.J. Kolff Institute for Biomedical Engineering and Materials Science, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands

314 citations

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TL;DR: In this article, the authors present a comprehensive and current overview of scientific advancement in liquid crystal and carbon nanotube suspension, focusing on the recent developments and fundamental understanding of carbon-nanotube dispersion in nematic liquid crystals.

143 citations

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TL;DR: To study the enzyme-like activity of nanoparticles, the electron spin resonance method represents a critically important and convenient analytical approach for zero-time detection of the reactive substrates and products as well as for mechanism determination.
Abstract: Due to possessing an extremely small size and a large surface area per unit of volume, nanomaterials have specific characteristic physical, chemical, photochemical, and biological properties that are very useful in many new applications. Nanoparticles' catalytic activity and intrinsic ability in generating or scavenging reactive oxygen species in general can be used to mimic the catalytic activity of natural enzymes. Many nanoparticles with enzyme-like activities have been found, potentially capable of being applied for commercial uses, such as in biosensors, pharmaceutical processes, and the food industry. To date, a variety of nanoparticles, especially those formed from noble metals, have been determined to possess oxidase-like, peroxidase-like, catalase-like, and/or superoxide dismutase-like activity. The ability of nanoparticles to mimic enzymatic activity, especially peroxidase mimics, can be used in a variety of applications, such as detection of glucose in biological samples and waste water treatment. To study the enzyme-like activity of nanoparticles, the electron spin resonance method represents a critically important and convenient analytical approach for zero-time detection of the reactive substrates and products as well as for mechanism determination.

139 citations