Assoc. Prof. Libor Kvítek, Ph.D.

2011

• R. Prucek, J. Tucek, M. Kilianova, A. Panacek, L. Kvitek, J. Filip, M. Kolar, K. Tomankova, and R. Zboril, “The targeted antibacterial and antifungal properties of magnetic
  nanocomposite of iron oxide and silver nanoparticles,” BIOMATERIALS, vol. 32, iss. 21, pp. 4704-4713, 2011.
  [Bibtex]

  @article ISI:000291571400003,
  Author = Prucek, Robert and Tucek, Jiri and Kilianova, Martina and Panacek, Ales
     and Kvitek, Libor and Filip, Jan and Kolar, Milan and Tomankova,
     Katerina and Zboril, Radek,
  Title = The targeted antibacterial and antifungal properties of magnetic
     nanocomposite of iron oxide and silver nanoparticles,
  Journal = BIOMATERIALS,
  Year = 2011,
  Volume = 32,
  Number = 21,
  Pages = 4704-4713,
  Month = JUL,
  Abstract = Two types of magnetic binary nanocomposites, Ag@Fe(3)O(4) and
     gamma-Fe(2)O(3)@Ag, were synthesized and characterized and their
     antibacterial activities were tested. As a magnetic component, Fe(3)O(4)
     (magnetite) nanoparticles with an average size of about 70 nm and
     monodisperse gamma-Fe(2)O(3) (maghemite) nanoparticles with an average
     size of 5 nm were used. Nanocomposites were prepared via in situ
     chemical reduction of silver ions by maltose in the presence of
     particular magnetic phase and molecules of polyacrylate serving as a
     spacer among iron oxide and silver nanoparticles. In the case of the
     Ag@Fe(3)O(4) nanocomposite, silver nanoparticles, caught at the surfaces
     of Fe(3)O(4) nanocrystals, were around 5 nm in a size. On the contrary,
     in the case of the gamma-Fe(2)O(3)@Ag nanocomposite, ultrafine
     gamma-Fe(2)O(3) nanoparticles surrounded silver nanoparticles ranging in
     a size between 20 and 40 nm. In addition, the molecules of polyacrylate
     in this nanocomposite type suppress considerably interparticle magnetic
     interactions as proved by magnetization measurements. Both synthesized
     nanocomposites exhibited very significant antibacterial and antifungal
     activities against ten tested bacterial strains (minimum inhibition
     concentrations (MIC) from 15.6 mg/L to 125 mg/L) and four candida
     species (MIC from 1.9 mg/L to 31.3 mg/L). Moreover, acute nanocomposite
     cytotoxicity against mice embryonal fibroblasts was observed at
     concentrations of higher than 430 mg/L (Ag@Fe(3)O(4)) and 292 mg/L
     (gamma-Fe(2)O(3)@Ag). With respect to the non-cytotoxic nature of the
     polyacrylate linker, both kinds of silver nanocomposites are well
     applicable for a targeted magnetic delivery of silver nanoparticles in
     medicinal and disinfection applications. (C) 2011 Elsevier Ltd. All
     rights reserved.,
  DOI = 10.1016/j.biomaterials.2011.03.039,
  ISSN = 0142-9612,
  Unique-ID = ISI:000291571400003,
  

• A. Panacek, R. Prucek, D. Safarova, M. Dittrich, J. Richtrova, K. Benickova, R. Zboril, and L. Kvitek, “Acute and Chronic Toxicity Effects of Silver Nanoparticles (NPs) on
  Drosophila melanogaster,” ENVIRONMENTAL SCIENCE & TECHNOLOGY, vol. 45, iss. 11, pp. 4974-4979, 2011.
  [Bibtex]

  @article ISI:000291128700045,
  Author = Panacek, Ales and Prucek, Robert and Safarova, Dana and Dittrich, Milan
     and Richtrova, Jana and Benickova, Katerina and Zboril, Radek and
     Kvitek, Libor,
  Title = Acute and Chronic Toxicity Effects of Silver Nanoparticles (NPs) on
     Drosophila melanogaster,
  Journal = ENVIRONMENTAL SCIENCE \& TECHNOLOGY,
  Year = 2011,
  Volume = 45,
  Number = 11,
  Pages = 4974-4979,
  Month = JUN 1,
  Abstract = The use of nanoscaled materials is rapidly increasing, however, their
     possible ecotoxicological effects are still not precisely known. This
     work constitutes the first complex study focused on in vivo evaluation
     of the acute and chronic toxic effects and toxic limits of silver
     nanoparticles (NPs) on the eukaryotic organism Drosophila melanogaster.
     For the purpose of this study, silver NPs were prepared in the form of
     solid dispersion using microencapsulation method, where mannitol was
     used as an encapsulation agent. This newly prepared solid dispersion
     with a high concentration of silver NPs was exploited to prepare the
     standard Drosophila culture medium at a silver concentration range from
     10 mg . L(-1) to 100 mg . L(-1) of Ag in the case of the acute toxicity
     testing and at a concentration equal to S mg . L in the case of the
     chronic toxicity testing. The acute toxic effect of silver NPs on
     Drosophila melanogaster was observed for the silver concentration equal
     to 20 mg . L(-1). At this silver concentration, 50\% of the tested flies
     were unable to leave the pupae, and they did not finish their
     developmental cycle. Chronic toxicity of silver NPs was assessed by a
     long-term exposure of overall eight filial generations of Drosophila
     melanogaster to silver NPs. The long-term exposure to silver NPs
     influenced the fertility of Drosophila during the first three filial
     generations, nevertheless the fecundity of flies in subsequent
     generations consequently increased up to the level of the flies from the
     control sample due to the adaptability of flies to the silver NPs
     exposure.,
  DOI = 10.1021/es104216b,
  ISSN = 0013-936X,
  Unique-ID = ISI:000291128700045,
  

• L. Kvitek and J. Hrbac, “Comment on “From Nanoparticles to Nanoplates: Preferential Oriented
  Connection of Ag Colloids during Electrophoretic Deposition”,” JOURNAL OF PHYSICAL CHEMISTRY C, vol. 115, iss. 11, pp. 4980-4981, 2011.
  [Bibtex]

  @article ISI:000288401200082,
  Author = Kvitek, Libor and Hrbac, Jan,
  Title = Comment on ``From Nanoparticles to Nanoplates: Preferential Oriented
     Connection of Ag Colloids during Electrophoretic Deposition'',
  Journal = JOURNAL OF PHYSICAL CHEMISTRY C,
  Year = 2011,
  Volume = 115,
  Number = 11,
  Pages = 4980-4981,
  Month = MAR 24,
  DOI = 10.1021/jp1061144,
  ISSN = 1932-7447,
  Unique-ID = ISI:000288401200082,
  

• R. Prucek, A. Panacek, J. Soukupova, R. Novotny, and L. Kvitek, “Reproducible synthesis of silver colloidal particles tailored for
  application in near-infrared surface-enhanced Raman spectroscopy,” JOURNAL OF MATERIALS CHEMISTRY, vol. 21, iss. 17, pp. 6416-6420, 2011.
  [Bibtex]

  @article ISI:000289524300045,
  Author = Prucek, Robert and Panacek, Ales and Soukupova, Jana and Novotny, Radko
     and Kvitek, Libor,
  Title = Reproducible synthesis of silver colloidal particles tailored for
     application in near-infrared surface-enhanced Raman spectroscopy,
  Journal = JOURNAL OF MATERIALS CHEMISTRY,
  Year = 2011,
  Volume = 21,
  Number = 17,
  Pages = 6416-6420,
  Abstract = Reproducible synthesis of silver colloidal particles, with diameters of
     hundreds of nanometres, represents an experimentally rather difficult
     task although they have revealed a great application potential in e. g.
     SERS. The newly developed method, based on the reduction of the complex
     anion [Ag(SO(3))(2)](3-), offers an approach enabling to manage the
     preparation of silver particles with adjustable average diameters in the
     interval from 200 nm up to 700 nm due to the choice of the reducing
     agent and the sulfite concentration. These particles proved their
     efficiency as substrates for surface enhanced Raman spectroscopy with
     the excitation in the near infrared region (lambda = 1064 nm) and
     therefore this newly developed method confirmed the expected application
     potential.,
  DOI = 10.1039/c0jm03870a,
  ISSN = 0959-9428,
  Unique-ID = ISI:000289524300045,
  

• R. Prucek, A. Panacek, A. Fargasova, V. Ranc, V. Masek, L. Kvitek, and R. Zboril, “Re-crystallization of silver nanoparticles in a highly concentrated NaCl
  environment-a new substrate for surface enhanced IR-visible Raman
  spectroscopy,” CRYSTENGCOMM, vol. 13, iss. 7, pp. 2242-2248, 2011.
  [Bibtex]

  @article ISI:000288562200014,
  Author = Prucek, Robert and Panacek, Ales and Fargasova, Ariana and Ranc, Vaclav
     and Masek, Vlastimil and Kvitek, Libor and Zboril, Radek,
  Title = Re-crystallization of silver nanoparticles in a highly concentrated NaCl
     environment-a new substrate for surface enhanced IR-visible Raman
     spectroscopy,
  Journal = CRYSTENGCOMM,
  Year = 2011,
  Volume = 13,
  Number = 7,
  Pages = 2242-2248,
  Abstract = The common approach of silver nanoparticles activation for surface
     enhanced Raman spectroscopy often exploits an addition of chloride ions,
     generally at low concentrations of about 0.1-10 mM in the final
     dispersion. For the first time, we report the applicability of a highly
     concentrated NaCl solution (final concentration of 400 mM) for the SERS
     activation of silver nanoparticles (similar to 30 nm). Microscopic,
     optical and particle size distribution measurements reveal the rapid and
     reproducible re-crystallization of the primary silver nanoparticles to
     one-order larger crystallites (similar to 400 nm) already after 15 min
     after NaCl addition. The crystal growth mechanism is discussed with
     respect to the proved essential role of oxygen in the reaction system.
     The specific action of chloride ions is demonstrated through a
     comparison with NaBr and NaI solutions of the identical concentrations,
     which do not induce the analogous crystallization process. The
     recrystallized silver particles are efficient in an enhancement of the
     Raman signal not only for visible (488 nm) but also for near infrared
     laser excitation (1064 nm) as illustrated with the representative
     spectra of adenine.,
  DOI = 10.1039/c0ce00776e,
  ISSN = 1466-8033,
  Unique-ID = ISI:000288562200014,
  

2010

• J. Soukupova, L. Kvitek, M. Kratochvilova, A. Panacek, R. Prucek, and R. Zboril, “Silver Voyage from Macro- to Nanoworld,” JOURNAL OF CHEMICAL EDUCATION, vol. 87, iss. 10, pp. 1094-1097, 2010.
  [Bibtex]

  @article ISI:000281834400024,
  Author = Soukupova, Jana and Kvitek, Libor and Kratochvilova, Martina and
     Panacek, Ales and Prucek, Robert and Zboril, Radek,
  Title = Silver Voyage from Macro- to Nanoworld,
  Journal = JOURNAL OF CHEMICAL EDUCATION,
  Year = 2010,
  Volume = 87,
  Number = 10,
  Pages = 1094-1097,
  Month = OCT,
  DOI = 10.1021/ed1003405,
  ISSN = 0021-9584,
  Unique-ID = ISI:000281834400024,
  

• M. Vanickova, J. Soukupova, and L. Kvitek, “Nanotechnology in Teaching Natural Science,” CHEMICKE LISTY, vol. 104, iss. 10, pp. 945-949, 2010.
  [Bibtex]

  @article ISI:000283622500008,
  Author = Vanickova, Marketa and Soukupova, Jana and Kvitek, Libor,
  Title = Nanotechnology in Teaching Natural Science,
  Journal = CHEMICKE LISTY,
  Year = 2010,
  Volume = 104,
  Number = 10,
  Pages = 945-949,
  Abstract = Nanomaterials are now produced in large quantities due to their useful
     properties different from other materials. Possible toxicity of
     nanomaterials is currently addressed and discussed. Using a modified
     Tollens process, an aqueous dispersion of Ag nanoparticles was prepared,
     on which their unique properties and changes of material characteristics
     when approaching nano dimensions can be demonstrated. Also, experiments
     regarding toxicity of nanoparticles were proposed. Toxicity of the
     nanoparticles was tested on Paramecium caudatum. Following the
     instruction, the students discover that the prepared Ag nanoparticles
     are much less toxic than ionic Ag. The proposed experiments bring
     interdisciplinary chemical, physical, and biological findings and
     knowledge.,
  ISSN = 0009-2770,
  Unique-ID = ISI:000283622500008,
  

2009

• A. Panacek, M. Kolar, R. Vecerova, R. Prucek, J. Soukupova, V. Krystof, P. Hamal, R. Zboril, and L. Kvitek, “Antifungal activity of silver nanoparticles against Candida spp.,” BIOMATERIALS, vol. 30, iss. 31, pp. 6333-6340, 2009.
  [Bibtex]

  @article ISI:000270767300020,
  Author = Panacek, Ales and Kolar, Milan and Vecerova, Renata and Prucek, Robert
     and Soukupova, Jana and Krystof, Vladimir and Hamal, Petr and Zboril,
     Radek and Kvitek, Libor,
  Title = Antifungal activity of silver nanoparticles against Candida spp.,
  Journal = BIOMATERIALS,
  Year = 2009,
  Volume = 30,
  Number = 31,
  Pages = 6333-6340,
  Month = NOV,
  Abstract = The antifungal activity of the silver nanoparticles (NPs) prepared by
     the modified Tollens process was evaluated for pathogenic Candida spp.
     by means of the determination of the minimum inhibitory concentration
     (MIC), minimum fungicidal concentration (MFC), and the time-dependency
     of yeasts growth inhibition. Simultaneously the cytotoxicity of the
     silver NPs to human fibroblasts was determined. The silver NPs exhibited
     inhibitory effect against the tested yeasts at the concentration as low
     as 0.21 mg/L of Ag. The inhibitory effect of silver NPs was enhanced
     through their stabilization and the lowest MIC equal to 0.05 mg/L was
     determined for silver NPs stabilized by sodium dodecyl sulfate against
     Candida albicans II. The obtained MICs of the silver NPs and especially
     of the stabilized silver NPs were comparable and in some cases even
     better than MICs of the conventional antifungal agents determined by
     E-test. The silver NPs effectively inhibited the growth of the tested
     yeasts at the concentrations below their cytotoxic limit against the
     tested human fibroblasts determined at a concentration equal to 30 mg/L
     of Ag. In contrast, ionic silver inhibited the growth of the tested
     yeasts at the concentrations comparable to the cytotoxic level (approx.
     1 mg/L) of ionic silver against the tested human fibroblasts. (C) 2009
     Elsevier Ltd. All rights reserved.,
  DOI = 10.1016/j.biomaterials.2009.07.065,
  ISSN = 0142-9612,
  Unique-ID = ISI:000270767300020,
  

• L. Kvitek, M. Vanickova, A. Panacek, J. Soukupova, M. Dittrich, E. Valentova, R. Prucek, M. Bancirova, D. Milde, and R. Zboril, “Initial Study on the Toxicity of Silver Nanoparticles (NPs) against
  Paramecium caudatum,” JOURNAL OF PHYSICAL CHEMISTRY C, vol. 113, iss. 11, pp. 4296-4300, 2009.
  [Bibtex]

  @article ISI:000264111300013,
  Author = Kvitek, Libor and Vanickova, Marketa and Panacek, Ales and Soukupova,
     Jana and Dittrich, Milan and Valentova, Eva and Prucek, Robert and
     Bancirova, Martina and Milde, David and Zboril, Radek,
  Title = Initial Study on the Toxicity of Silver Nanoparticles (NPs) against
     Paramecium caudatum,
  Journal = JOURNAL OF PHYSICAL CHEMISTRY C,
  Year = 2009,
  Volume = 113,
  Number = 11,
  Pages = 4296-4300,
  Month = MAR 19,
  Abstract = In this initial study, the toxicity effect of silver NPs against a model
     unicellular eukaryotic organism of Paramecium caudatum was studied. For
     the purpose of this study, a dialysis-based method was adapted, which
     allowed the preparation of stable aqueous dispersions of silver NPs in
     various silver concentrations that were necessary for the evaluation of
     toxicity limits of these particles. The obtained results demonstrate
     that the silver NPs do not exhibit any toxicity action against the
     tested unicellular eukaryotic organism below the concentration of 25 mg
     . L(-1) whereas ionic silver retains its toxicity even at a
     concentration of 0.4 mg . L(-1). Such a considerable difference in the
     toxicity effect of these two forms of silver has not been observed in
     the previously published study concerning bacteria (Panacek, A.; Kvitek,
     L.; Prucek, R.; Koldr, M.; Vecefova, R.; Pizurova, N.; Sharma, V. K.;
     Nevecna, T.; Zboril, R. J. Phys. Chem. B 2006, 110, 16248-16253).
     Additionally, it was proven that the surfactant/polymer modification can
     increase the toxicity of the silver NPs against the tested organism.,
  DOI = 10.1021/jp808645e,
  ISSN = 1932-7447,
  Unique-ID = ISI:000264111300013,
  

• L. Kvitek and J. Soukupova, “Comment on `Preparation and antibacterial activity of Fe(3)O(4)@ Ag
  nanoparticles’,” NANOTECHNOLOGY, vol. 20, iss. 2, 2009.
  [Bibtex]

  @article ISI:000261647500024,
  Author = Kvitek, Libor and Soukupova, Jana,
  Title = Comment on `Preparation and antibacterial activity of Fe(3)O(4)@ Ag
     nanoparticles',
  Journal = NANOTECHNOLOGY,
  Year = 2009,
  Volume = 20,
  Number = 2,
  Month = JAN 14,
  Abstract = The fabrication of nanocomposite materials with a metal-oxide@
     nobel-metal structure represents a challenge both from the theoretical
     and experimental points of view. This challenge is connected with a
     complicated mechanism of formation of these nanocomposite materials. In
     the paper by Gong et al (2007 Nanotechnology 18 285604), the authors
     tried to solve this problem but the suggested mechanism is rather
     improbable. This improbability derived from the found discrepancy in the
     material balance of reactants/ products. Therefore this comment is
     devoted to evaluation of this discrepancy of the Fe(3)O(4)@ Ag
     nanoparticle preparation and suggestion of another possible mechanism.,
  DOI = 10.1088/0957-4484/20/2/028001,
  Article-Number = 028001,
  ISSN = 0957-4484,
  Unique-ID = ISI:000261647500024,
  

• R. Prucek, L. Kvitek, A. Panacek, L. Vancurova, J. Soukupova, D. Jancik, and R. Zboril, “Polyacrylate-assisted synthesis of stable copper nanoparticles and
  copper(I) oxide nanocubes with high catalytic efficiency,” JOURNAL OF MATERIALS CHEMISTRY, vol. 19, iss. 44, pp. 8463-8469, 2009.
  [Bibtex]

  @article ISI:000271744600027,
  Author = Prucek, Robert and Kvitek, Libor and Panacek, Ales and Vancurova, Lenka
     and Soukupova, Jana and Jancik, Dalibor and Zboril, Radek,
  Title = Polyacrylate-assisted synthesis of stable copper nanoparticles and
     copper(I) oxide nanocubes with high catalytic efficiency,
  Journal = JOURNAL OF MATERIALS CHEMISTRY,
  Year = 2009,
  Volume = 19,
  Number = 44,
  Pages = 8463-8469,
  Abstract = The synthesis of Cu nanoparticles (NPs) via the reduction of Cu ions
     with sodium borohydride in the presence of sodium polyacrylate is
     presented. The final Cu nanocrystals having a 14 nm diameter were
     generated via the aggregation and coalescence of the primarily formed
     ultrasmall particles (approx. 3 nm). Addition of sodium sulfite to the
     dispersions provided the protection of the Cu NPs against oxidation. On
     the other hand, the controlled aeration of the Cu NPs resulted in their
     transformation to Cu(2)O nanocubes with an average size of 18 nm. Both
     Cu NPs and Cu(2)O nanocubes can effectively catalyze reduction of
     4-nitrophenol by sodium borohydride in aqueous solution.,
  DOI = 10.1039/b913561h,
  ISSN = 0959-9428,
  Unique-ID = ISI:000271744600027,
  

• H. Strnadova and L. Kvitek, “The Influence of Buffer on Self-Assembling Properties of Micelles,” CHEMICKE LISTY, vol. 103, iss. 4, pp. 315-319, 2009.
  [Bibtex]

  @article ISI:000265518100010,
  Author = Strnadova, Hana and Kvitek, Libor,
  Title = The Influence of Buffer on Self-Assembling Properties of Micelles,
  Journal = CHEMICKE LISTY,
  Year = 2009,
  Volume = 103,
  Number = 4,
  Pages = 315-319,
  Abstract = The values of CMC (critical micellar concentration) for buffered
     surfactant solutions used in separation methods in analytical chemistry,
     especially in micellar electrokinetic capillary chromatography, were
     studied by conductivity, surface tension and viscosity measurements. The
     study involved solutions of representative anionic (SDS), cationic
     (CTAB), and non-ionic (TX100, GX080) surfactants. The data measured for
     aqueous Solutions were in good agreement with the published data. The
     data for buffer solutions confirmed theoretical presumptions - the CMC
     values decreased with increasing ionic strength of the solutions. In
     contrast, viscoelastic properties of the solutions of surfactants were
     not significantly influenced by the ionic strength or pH of the
     solutions.,
  ISSN = 0009-2770,
  Unique-ID = ISI:000265518100010,
  

2008

• J. Soukupova, L. Kvitek, A. Panacek, T. Nevecna, and R. Zboril, “Comprehensive study on surfactant role on silver nanoparticles (NPs)
  prepared via modified Tollens process,” MATERIALS CHEMISTRY AND PHYSICS, vol. 111, iss. 1, pp. 77-81, 2008.
  [Bibtex]

  @article ISI:000257450300017,
  Author = Soukupova, Jana and Kvitek, Libor and Panacek, Ales and Nevecna,
     Tat'jana and Zboril, Radek,
  Title = Comprehensive study on surfactant role on silver nanoparticles (NPs)
     prepared via modified Tollens process,
  Journal = MATERIALS CHEMISTRY AND PHYSICS,
  Year = 2008,
  Volume = 111,
  Number = 1,
  Pages = 77-81,
  Month = SEP 15,
  Abstract = Surfactants represent not only commonly used wetting agents but also
     substances that can be used as growth modifiers in the process of solid
     nanoparticle (NP) preparation. In this study we report influential
     character of different types of surfactants - i.e. ionic (SDS, CTAC) and
     non-ionic (Tween 80) - on fundamental characteristics of silver NPs,
     which were prepared by a modified Tollens process. The influential
     character of surfactants was evaluated throughout a reasonable
     improvement of the polyclispersity (in the case of the tested non-ionic
     surfactants from 8.5\% even down to 2.5\%) and in the case of ionic
     surfactant, SDS and CTAC, also significant change of zeta potential
     (from -20 to -50 mV for the highest tested concentration of SDS). A
     slight influence of the tested surfactants was observed on the sizes of
     the prepared silver NPs. Therefore the obtained results from the
     performed surfactant-assisted syntheses revealed a possibility how to
     tailor silver NPs by means of their polydispersity and zeta potential
     according to the application demands. (c) 2008 Elsevier B.V. All rights
     reserved.,
  DOI = 10.1016/j.matchemphys.2008.03.018,
  ISSN = 0254-0584,
  Unique-ID = ISI:000257450300017,
  

• L. Kvitek, A. Panacek, J. Soukupova, M. Kolar, R. Vecerova, R. Prucek, M. Holecova, and R. Zboril, “Effect of surfactants and polymers on stability and antibacterial
  activity of silver nanoparticles (NPs),” JOURNAL OF PHYSICAL CHEMISTRY C, vol. 112, iss. 15, pp. 5825-5834, 2008.
  [Bibtex]

  @article ISI:000254883100021,
  Author = Kvitek, Libor and Panacek, Ales and Soukupova, Jana and Kolar, Milan and
     Vecerova, Renata and Prucek, Robert and Holecova, Mirka and Zboril,
     Radek,
  Title = Effect of surfactants and polymers on stability and antibacterial
     activity of silver nanoparticles (NPs),
  Journal = JOURNAL OF PHYSICAL CHEMISTRY C,
  Year = 2008,
  Volume = 112,
  Number = 15,
  Pages = 5825-5834,
  Month = APR 17,
  Abstract = In this first systematic study, we describe the influence of various
     surfactants and polymers on aggregation stability and antibacterial
     activity of silver nanoparticles (NPs) prepared by a modified Tollens
     process. The surfactant/polymer stabilizing effect was monitored using
     the newly established method based on a titration of the aqueous
     dispersion of the silver NPs by aqueous solution of
     poly(diallyldimethylammonium) chloride (PDDA). The aggregation process
     was evaluated by the dynamic light scattering (DLS) and UV/vis spectra
     measurements and finally confirmed by TEM. Among all of the investigated
     modifiers, two surfactants (sodium dodecyl sulfate-SDS and
     polyoxyethylenesorbitane monooleate-Tween 80) and one polymer
     (polyvinylpyr-rolidone-PVP 360) exhibit superior stabilization of the
     silver NP dispersions against the process of aggregation. The
     differences in the stabilization ability of various tested substances
     are discussed with respect to their structure and possible mechanism of
     the surface interaction with the NPs. The antibacterial activity of the
     modified silver NPs was significantly enhanced especially when modified
     by SDS where the minimum inhibition concentration (MIC) decreased under
     the ``magical value'' of 1 mu g(.)mL(-1). A correlation was found
     between the aggregation stability and enhanced antibacterial activity in
     the system of the silver NPs modified by SDS, Tween 80, and high
     molecular polymer PVP 360.,
  DOI = 10.1021/jp711616v,
  ISSN = 1932-7447,
  Unique-ID = ISI:000254883100021,
  

2006

• A. Panacek, L. Kvitek, R. Prucek, M. Kolar, R. Vecerova, N. Pizurova, V. K. Sharma, T. Nevecna, and R. Zboril, “Silver colloid nanoparticles: Synthesis, characterization, and their
  antibacterial activity,” JOURNAL OF PHYSICAL CHEMISTRY B, vol. 110, iss. 33, pp. 16248-16253, 2006.
  [Bibtex]

  @article ISI:000239818000019,
  Author = Panacek, Ales and Kvitek, Libor and Prucek, Robert and Kolar, Milan and
     Vecerova, Renata and Pizurova, Nadezda and Sharma, Virender K. and
     Nevecna, Tat'jana and Zboril, Radek,
  Title = Silver colloid nanoparticles: Synthesis, characterization, and their
     antibacterial activity,
  Journal = JOURNAL OF PHYSICAL CHEMISTRY B,
  Year = 2006,
  Volume = 110,
  Number = 33,
  Pages = 16248-16253,
  Month = AUG 24,
  Abstract = A one-step simple synthesis of silver colloid nanoparticles with
     controllable sizes is presented. In this synthesis, reduction of
     [Ag(NH3)(2)](+) complex cation by four saccharides was performed. Four
     saccharides were used: two monosaccharides (glucose and galactose) and
     two disaccharides (maltose and lactose). The syntheses performed at
     various ammonia concentrations (0.005-0.20 mol L-1) and pH conditions
     (11.5-13.0) produced a wide range of particle sizes (25-450 nm) with
     narrow size distributions, especially at the lowest ammonia
     concentrations. The average size, size distribution, morphology, and
     structure of particles were determined by dynamic light scattering
     (DLS), transmission electron microscopy (TEM), and UV/Visible absorption
     spectrophotometry. The influence of the saccharide structure
     (monosacharides versus disaccharides) on the size of silver particles is
     briefly discussed. The reduction of [Ag(NH3)(2)](+) by maltose
     produced silver particles with a narrow size distribution with an
     average size of 25 nm, which showed high antimicrobial and bactericidal
     activity against Gram-positive and Gram-negative bacteria, including
     highly multiresistant strains such as methicillin-resistant
     Staphylococcus aureus. Antibacterial activity of silver nanoparticles
     was found to be dependent on the size of silver particles. A very low
     concentration of silver (as low as 1.69 mu g/mL Ag) gave antibacterial
     performance.,
  DOI = 10.1021/jp063826h,
  ISSN = 1520-6106,
  Unique-ID = ISI:000239818000019,
  

2005

• A. Panacek and L. Kvitek, “Colloid chemistry in laboratory practice,” CHEMICKE LISTY, vol. 99, iss. 8, pp. 606-609, 2005.
  [Bibtex]

  @article ISI:000231377100009,
  Author = Panacek, A and Kvitek, L,
  Title = Colloid chemistry in laboratory practice,
  Journal = CHEMICKE LISTY,
  Year = 2005,
  Volume = 99,
  Number = 8,
  Pages = 606-609,
  Abstract = The aim of the article is to supply a current missing field of chemistry
     in grammar schools by project of simple practical problems from coloid
     chemistry. It contains teoretical part and practical problems focusing
     on physical and chemical properties of colloid chemistry.,
  ISSN = 0009-2770,
  Unique-ID = ISI:000231377100009,
  

• L. Kvitek, R. Prucek, A. Panacek, R. Novotny, J. Hrbac, and R. Zboril, “The influence of complexing agent concentration on particle size in the
  process of SERS active silver colloid synthesis,” JOURNAL OF MATERIALS CHEMISTRY, vol. 15, iss. 10, pp. 1099-1105, 2005.
  [Bibtex]

  @article ISI:000227320600013,
  Author = Kvitek, L and Prucek, R and Panacek, A and Novotny, R and Hrbac, J and
     Zboril, R,
  Title = The influence of complexing agent concentration on particle size in the
     process of SERS active silver colloid synthesis,
  Journal = JOURNAL OF MATERIALS CHEMISTRY,
  Year = 2005,
  Volume = 15,
  Number = 10,
  Pages = 1099-1105,
  Abstract = A one-step chemical reduction route towards silver colloid particles
     with controllable sizes ranging from 45 to 380 nm is reported in this
     article. Silver particles, prepared by the reduction of
     [Ag(NH3)(2)](+) complex with various reducing sugars, were
     characterised by means of transmission electron microscopy ( TEM),
     dynamic light scattering ( DLS) measurement of particle size
     distribution, and UV-VIS spectroscopy. The concentration of ammonia in
     the reaction mixture and the choice of the reducing sugar are the key
     parameters in the control of particle size. Synthesised silver colloid
     particles were successfully tested for use in surface-enhanced Raman
     spectroscopy (SERS) with 1-methyladenine as a testing substance.,
  DOI = 10.1039/b417007e,
  ISSN = 0959-9428,
  Unique-ID = ISI:000227320600013,
  

2004

• K. Mrkvova, J. Kamenicek, Z. Sindelar, L. Kvitek, J. Mrozinski, M. Nahorska, and D. Zak, “Synthesis, properties and crystal structures of R[M-III(bdt)(2)]
  complexes (M = Ni, Co, Cu),” TRANSITION METAL CHEMISTRY, vol. 29, iss. 3, pp. 238-244, 2004.
  [Bibtex]

  @article ISI:000220303000002,
  Author = Mrkvova, K and Kamenicek, J and Sindelar, Z and Kvitek, L and Mrozinski,
     J and Nahorska, M and Zak, D,
  Title = Synthesis, properties and crystal structures of R[M-III(bdt)(2)]
     complexes (M = Ni, Co, Cu),
  Journal = TRANSITION METAL CHEMISTRY,
  Year = 2004,
  Volume = 29,
  Number = 3,
  Pages = 238-244,
  Month = APR,
  Abstract = New nickel, cobalt and copper complexes with benzene- 1,2-dithiole
     (bdt), of general formula R[M(bdt)(2)]: M = Ni, Co and Cu; R = Me4N,
     Et4N, Pr4N, Me3PhN, MePh3P, Ph4P have been synthesized and characterized
     by standard physico-chemical methods (elemental analyses,
     magnetochemical and conductivity measurements, i. r. and u.v.- vis.
     spectroscopy). X-ray structural analysis of (MePh3P)[M(bdt)(2)], M =
     Ni, Co and Cu, confirms that the MS4 chromophore lies in a slightly
     distorted square coordination arrangement around the central atom. The
     three complexes have also been studied by cyclic voltammetry.,
  DOI = 10.1023/B:TMCH.0000020349.69302.37,
  ISSN = 0340-4285,
  Unique-ID = ISI:000220303000002,
  

• A. Panacek, L. Kvitek, and M. Kleckova, “Colloid chemistry in practical problems,” CHEMICKE LISTY, vol. 98, iss. 1, pp. 39-41, 2004.
  [Bibtex]

  @article ISI:000188806900008,
  Author = Panacek, A and Kvitek, L and Kleckova, M,
  Title = Colloid chemistry in practical problems,
  Journal = CHEMICKE LISTY,
  Year = 2004,
  Volume = 98,
  Number = 1,
  Pages = 39-41,
  Abstract = The aim of the article is giving an idea to secondary school
     schoolchildren of a neglected field of chemistry. It contains basic
     theoretical concepts from colloid chemistry and in particular
     instructions for practical problems of colloid chemistry. The problems
     are not time-, material- or tabour-consuming; they are focused on
     preparation of colloidal systems of inorganic materials and observation
     of their properties such as stability, stabilization and the Tyndall
     effect.,
  ISSN = 0009-2770,
  Unique-ID = ISI:000188806900008,
  

2003

• P. Kopel, Z. Travnicek, L. Kvitek, Z. Cernosek, G. Wrzeszcz, and J. Marek, “Synthesis and characterization of Cu(II), Co(II) and Ni(II) complexes of
  trithiocyanuric acid: The structure of \N,N
  `-bis(3-aminopropyl)-1,3-propane-diamine\-(trithiocyanurato)nickel(II),” JOURNAL OF COORDINATION CHEMISTRY, vol. 56, iss. 1, pp. 1-11, 2003.
  [Bibtex]

  @article ISI:000181343900001,
  Author = Kopel, P and Travnicek, Z and Kvitek, L and Cernosek, Z and Wrzeszcz, G
     and Marek, J,
  Title = Synthesis and characterization of Cu(II), Co(II) and Ni(II) complexes of
     trithiocyanuric acid: The structure of \N,N
     `-bis(3-aminopropyl)-1,3-propane-diamine\-(trithiocyanurato)nickel(II),
  Journal = JOURNAL OF COORDINATION CHEMISTRY,
  Year = 2003,
  Volume = 56,
  Number = 1,
  Pages = 1-11,
  Month = JAN 10,
  Abstract = Copper, cobalt and nickel complexes with nitrogen donor ligands and
     trithiocyanurate dianion (ttcH(2-)) have been prepared and characterized
     by elemental analysis, electronic and EPR (copper complexes) spectra,
     and magnetic susceptibility measurements over the temperature range
     78-291 K. Some of the complexes have also been studied by thermal
     analysis and by cycle voltammetry. Structures of the complexes have been
     proposed on the basis of magnetic and spectral properties. Two copper
     complexes of compositions Cu(bpy)(ttcH) and Cu(phen)(ttcH), where
     bpy=2,2'-bipyridine, phen=1,10-phenanthroline, are probably polymeric,
     whereas the copper complex with N,N-bis(3-aminopropyl)ethylenediamine
     (bapen) of composition [Cu(bapen)ttcH)](.)2H(2)O is mononuclear. We
     assume distorted octahedral structures for nickel complexes, A single
     crystal X-ray analysis of [Ni(bappn)(ttcH)](.)5H(2)O shows that the
     central nickel atom is coordinated by tetradentate nitrogen ligand
     N,N'-bis(3-aminopropyl)-1,3-propanediamine and coordination is completed
     by sulfur and nitrogen atoms of trithiocyanurate dianion.,
  DOI = 10.1080/0095897021000039034,
  ISSN = 0095-8972,
  Unique-ID = ISI:000181343900001,
  

2001

• P. Kopel, Z. Travnicek, L. Kvitek, M. Biler, M. Pavlicek, Z. Sindelar, and J. Marek, “Coordination compounds of nickel with trithiocyanuric acid. Part IV.
  Structure of [Ni(pmdien)(ttcH)] (pmdien = N,N,N `,N `,N
  `’-pentamethyldiethylenetriamine, ttcH(3) = trithiocyanuric acid),” TRANSITION METAL CHEMISTRY, vol. 26, iss. 3, pp. 282-286, 2001.
  [Bibtex]

  @article ISI:000167436200007,
  Author = Kopel, P and Travnicek, Z and Kvitek, L and Biler, M and Pavlicek, M and
     Sindelar, Z and Marek, J,
  Title = Coordination compounds of nickel with trithiocyanuric acid. Part IV.
     Structure of [Ni(pmdien)(ttcH)] (pmdien = N,N,N `,N `,N
     `'-pentamethyldiethylenetriamine, ttcH(3) = trithiocyanuric acid),
  Journal = TRANSITION METAL CHEMISTRY,
  Year = 2001,
  Volume = 26,
  Number = 3,
  Pages = 282-286,
  Month = JUN,
  Abstract = Ni-II mixed-ligand complexes of compositions [Ni(pmdien)(ttcH)] (1),
     [Ni(baphen)(2)(ttcH)] . 4H(2)O (2), [Ni-(dpa)(ttcH)(H2O)] (3),
     [Ni(cyclam)(ttcH)] . 2H(2)O (4), [Ni(hexaa)](ttcH) (5) and
     [Ni(hexab)(ttcH)] . 2H(2)O (6), (baphen =
     4,7-diphenyl-1,10-phenanthroline, dpa = 2,2'-dipyridylamine, cyclam =
     1,4,8,11-tetraazacyclotetradecane, hexaa =
     1,3,6,9,11,14-hexaazatricyclo[12.2.1.1(6),9]-octadecane, hexab =
     1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane) have been prepared
     and characterized by means of i.r., u.v.-vis. spectroscopies and
     magnetochemical measurements. The redox properties of the complexes were
     studied by cyclic voltammetry. The crystal and molecular structure of
     [Ni(pmdien)(ttcH)] was determined. The nickel atom is
     penta-coordinated by three N atoms of pmdien, and by S and N atoms of
     trithiocyanurate(2-) anion.,
  DOI = 10.1023/A:1007129711379,
  ISSN = 0340-4285,
  Unique-ID = ISI:000167436200007,
  

2000

• V. Machala, Z. Travnicek, Z. Sindelar, L. Kvitek, and J. Marek, “Nitrogen-donor base adducts of bis(O,O
  `-di-isoamyldithiophosphato)nickel(II),” TRANSITION METAL CHEMISTRY, vol. 25, iss. 6, pp. 715-719, 2000.
  [Bibtex]

  @article ISI:000089150700022,
  Author = Machala, V and Travnicek, Z and Sindelar, Z and Kvitek, L and Marek, J,
  Title = Nitrogen-donor base adducts of bis(O,O
     `-di-isoamyldithiophosphato)nickel(II),
  Journal = TRANSITION METAL CHEMISTRY,
  Year = 2000,
  Volume = 25,
  Number = 6,
  Pages = 715-719,
  Month = DEC,
  Abstract = A series of Ni-II complexes with the O,O'-di-isoamylester of
     dithiophosphoric acid and nitrogen-donor ligands of composition
     [Ni(i-Am(2)dtp)(2)(L)]; [dtp = O2PS2-; L = 2,2'-bipyridine (bpy);
     1,10-phenanthroline (phen); 5-nitro-1,10-phenanthroline (nphen);
     4,7-diphenyl-1,10-phenanthroline (baphen);
     2,9-dimethyl-1,10-phenanthroline (neo), 2-aminomethylpyridine (amp),
     2-(2-aminoethyl)pyridine (aep), 2,2'-dipiridylamine (dpa),
     1,2-diaminopropane (1,2-dap) or trans 1,2-diaminocyclohexane (dch)] have
     been prepared. The compounds have been characterized by elemental
     analyses (C,H,N,S), electronic and i.r. spectroscopy, magnetic and
     conductivity measurements and by cyclic voltammetry. The results show
     that all complexes behave as non-electrolytes in acetone. Electronic
     spectra and magnetic moments suggest a distorted cis-octahedral geometry
     around the Ni-II atom [mu(eff)/mu(B) is an element of < 3.10, 3.40 >],
     except for [Ni(i-Am(2)dtp)(2)(aep)], where the measured temperature
     dependence of the magnetic susceptibility proved the tetrahedrally
     coordinated nickel [4.06 mu(eff)/mu(B) (298 K) - 3.20 mu(eff)/mu(B)
     (80 K)]. In the [Ni(i-Am(2)dtp)(2)(neo)] complex, the nickel atom is
     penta-coordinated. The X-ray crystal and molecular structure of
     [Ni(i-Am(2)dtp)(2)(1,2-dap)] has been determined.,
  DOI = 10.1023/A:1007016617249,
  ISSN = 0340-4285,
  Unique-ID = ISI:000089150700022,
  

1999

• Z. Travnicek, J. Walla, L. Kvitek, Z. Sindelar, and M. Biler, “Xanthate complexes of nickel with nitrogen donor ligands. Part V,” TRANSITION METAL CHEMISTRY, vol. 24, iss. 6, pp. 633-637, 1999.
  [Bibtex]

  @article ISI:000083275300004,
  Author = Travnicek, Z and Walla, J and Kvitek, L and Sindelar, Z and Biler, M,
  Title = Xanthate complexes of nickel with nitrogen donor ligands. Part V,
  Journal = TRANSITION METAL CHEMISTRY,
  Year = 1999,
  Volume = 24,
  Number = 6,
  Pages = 633-637,
  Month = DEC,
  Abstract = Nickel(II) xanthate complexes of general formula, [Ni(Rxa)(2)(L)] [R
     = i-Pr, i-Am, xa = OCS2-, L = 4,7-diphenyl-1,10-phenanthroline(baphen),
     4,4'-dimethyl-2,2'-bipyridyl (me(2)bpy),
     2-9-dimethyl-1,10-phenanthroline(neo) or trans-1,2-diaminocyclohexane
     (dch)] and [Ni(Rxa)(cyclam)](Rxa) ( =
     1,4,8,11-tetraazacyclotetradecane) have been synthesized and
     characterized by elemental analyses, i.r. and electronic spectroscopy,
     magnetic and conductivity measurements. The complexes with cyclam were
     studied by cyclic voltammetry. Values of magnetic moments at room
     temperature lie within the 3.25-3.51 B.M. range and thus indicate the
     presence of two unpaired electrons, except for the complexes with
     cyclam, where the anomalous values of 1.76 and 1.74 B.M. were obtained
     in respect to the nickel(II) complexes. Magnetic susceptibility data for
     [Ni(i-Prxa)(cyclam)](i-Prxa) were measured over the 79-298 K range and
     indicate no exchange interaction between paramagnetic nickel(II)
     centres.,
  DOI = 10.1023/A:1006923722773,
  ISSN = 0340-4285,
  Unique-ID = ISI:000083275300004,
  

• F. Brezina, Z. Sindelar, L. Kvitek, and R. Pastorek, “Synthesis and magnetic properties of dithiooxamide-bridged nickel(II)
  complexes,” TRANSITION METAL CHEMISTRY, vol. 24, iss. 1, pp. 88-91, 1999.
  [Bibtex]

  @article ISI:000080479500021,
  Author = Brezina, F and Sindelar, Z and Kvitek, L and Pastorek, R,
  Title = Synthesis and magnetic properties of dithiooxamide-bridged nickel(II)
     complexes,
  Journal = TRANSITION METAL CHEMISTRY,
  Year = 1999,
  Volume = 24,
  Number = 1,
  Pages = 88-91,
  Month = FEB,
  Abstract = Two novel nickel(II) dinuclear complexes
     [Ni-2(cyclam)(2)(DTA)](ClO4)(2) (1) and [Ni-2(TAA)(2)(DTA)]
     (ClO4)(2) (2) (TAA = N(CH2CH2NH2)(3), cyclam =
     1,4,8,11-tetraazacyclotetradecane, DTA = dithiooxamide) have been
     prepared and studied by elemental analyses, i.r. and electronic spectra
     and magnetic measurements. The magnetic susceptibility temperature
     dependence was measured over the 77-300 K range and the observed data
     were successfully simulated by an equation based on the spin Hamiltonian
     operator (H = -2JS(1)S(2)) giving the exchange integral J = -23.09
     cm(-1) for (1) and J = -26.0 cm(-1) for (2).,
  DOI = 10.1023/A:1006997924748,
  ISSN = 0340-4285,
  Unique-ID = ISI:000080479500021,
  

• P. Kopel, Z. Travnicek, L. Kvitek, R. Panchartkova, M. Biler, J. Marek, and M. Nadvornik, “Coordination compounds of nickel with trithiocyanuric acid – Part III.
  Crystal and molecular structure of [Ni(bapen)(ttcH)]center dot 2H(2)O
  (bapen=N,N `-bis(3-aminopropyl)ethylenediamine, ttcH(3) =
  trithiocyanuric acid),” POLYHEDRON, vol. 18, iss. 12, pp. 1779-1784, 1999.
  [Bibtex]

  @article ISI:000080990300010,
  Author = Kopel, P and Travnicek, Z and Kvitek, L and Panchartkova, R and Biler, M
     and Marek, J and Nadvornik, M,
  Title = Coordination compounds of nickel with trithiocyanuric acid - Part III.
     Crystal and molecular structure of [Ni(bapen)(ttcH)]center dot 2H(2)O
     (bapen=N,N `-bis(3-aminopropyl)ethylenediamine, ttcH(3) =
     trithiocyanuric acid),
  Journal = POLYHEDRON,
  Year = 1999,
  Volume = 18,
  Number = 12,
  Pages = 1779-1784,
  Abstract = Coordination compounds of compositions [Ni(bapen)(ttcH)] . 2H(2)O (1),
     [Ni(bappn)(ttcH)] (2), [Ni(mdpta)(ttcH)(H2O)] (3),
     [Ni(nphen)(2)(ttcH)] . H2O (4), [Ni(nphen)(3)](ttcH). 2H(2)O (5),
     [Ni(ampy)(2)(ttcH). H2O (6) and [Ni(aepy)(2)(ttcH)]. 2H(2)O (7),
     where bapen = N,N'-bis(3-aminopropyl)ethylenediamine, bappn = N,N'-bis(
     3-aminopropyl)-1,3-propanediamine, mdpta =
     3,3'-diamino-N-methyldipropylamine, nphen=5-nitro-1,10-phenanthroline,
     ampy = 2-aminomethylpyridine, aepy = 2-aminoethylpyridine and ttcH(3) =
     trithiocyanuric acid, have been prepared. The crystal and molecular
     structure of (1) was determined by X-ray analysis. Nickel atom is
     six-coordinated by four N atoms of amine and S and N donor atoms of
     trithiocyanuric dianion, whereas two water molecules are situated
     outside the coordination sphere. Cyclic voltammetry showed that the
     complexes undergo an oxidation attributable to Ni2+-->Ni3+ in the range
     550-950 mV. The magnetic behaviour of (6) and (7) has been studied in
     the 291-94 K temperature range. Magnetic susceptibility follows the
     Curie-Weiss law. (C) 1999 Elsevier Science Ltd. All rights reserved.,
  DOI = 10.1016/S0277-5387(99)00053-4,
  ISSN = 0277-5387,
  Unique-ID = ISI:000080990300010,
  

1998

• L. Kvitek, R. Novotny, and P. Pikal, “Size determination of inorganic particles by dynamic light scattering,” CHEMICKE LISTY, vol. 92, iss. 5, pp. 431-433, 1998.
  [Bibtex]

  @article ISI:000073838700007,
  Author = Kvitek, L and Novotny, R and Pikal, P,
  Title = Size determination of inorganic particles by dynamic light scattering,
  Journal = CHEMICKE LISTY,
  Year = 1998,
  Volume = 92,
  Number = 5,
  Pages = 431-433,
  Abstract = The size distributions of particles in aqueous dispersions of TiO2 and
     Fe2O3 determined by dynamic light scattering were compared with the size
     distributions obtained by electron microscopy and gravitation
     sedimentation. Very good accordance of these methods has been found for
     TiO2 whereas Fe2O3 showed significant deviations in the similar sets of
     values, probably due to a strong tendency to particle agglomeration.,
  ISSN = 0009-2770,
  Unique-ID = ISI:000073838700007,