New Era in Nanoparticles and Interfaces

International symposium during fall meeting of polymer society of Korea (PSK)
October 7 in Daegu EXCO, South Korea 

Supported by TMRC at SKKU, SKKU Energy Science BK21 program, Korean NRF, Porous Nanoparticles Bank
Symposium Organizers:  Gi-Ra Yi (ChE, SKKU) Pil Jin Yoo (ChE, SKKU)

Invited Speakers

 Ludwik Leibler 
(ESPCI, France) CV ​
(Physics, N​YU​, USA) 
(Chemistry, NYU​, USA) ​
(SEAS, UPenn​, USA) 
Frank Caruso 
(ChE, U. Melbourne, Australia)
Bartosz Grzybowski
(Chemistry, UNIST, Korea) 
Yung Doug Suh 
(Physics, SKKU, Korea) 

  • Schedule (10/7 (Wed) 1:30PM-5:30PM)

1:30 PM-2:00PM David Pine 
         Self-assembly of colloids with directional and specific interactions
2:00 PM-2:30PM Daeyeon Lee 
         Continuous Generation of Bijel Microparticles, Fibers and Films
         Using Solvent Transfer-Induced Phase Separation (STRIPS)
2:30 PM-3:00PM Stefano Sacanna
         Anisotropic colloids via stimulated dewetting
3:00 PM-3:30PM Frank Caruso
         Engineering interfaces and particles through the assembly of metal–phenolic networks
3:30 PM-4:00PM Ludwik Leibler
         Nanoparticles dispersions as adhesives for gels and biological tissues
4:00 PM-4:30PM Yung Doug Suh
        Nano-gap Enhanced Raman Scattering(NERS) controlled by DNA 
4:30 PM-5:00PM Bartosz Grzybowski
         Self-assembly, trapping and manipulation of nonmagnetic microobjects with magnetic fields.
5:00 PM-5:30PM Sung Ha Park
         DNA Nanostructures and their Applications


  • Nanoparticles dispersions as adhesives for gels and biological tissues

    Ludwik Leibler
    Matière Molle et Chimie, ESPCI ParisTech, 10 rue Vauquelin,  75005 Paris, France

    Adhesives and glues are made of polymers. We introduce a novel concept of adhesion by particle solutions. We will demonstrate that to make a strong junction between two surfaces it suffices to spread a drop of a particle solution on one surface and press the other into a contact for few seconds. We will show the efficiency of the method, which we call nanobridging, for natural and synthetic hydrogels and various sorts of particles such as silica or iron oxide. We then extend the concept of nanobridging to biological tissues and demonstrate that the method can be used in vivo to close wounds even for soft organs such as liver and in hemorrhagic conditions.  We will also show how particles can be used for hemostasis after organ resection. The approach proved easy to apply, rapid and efficient in situations when conventional methods of suturing or stapling are traumatic or fail. 

  • Engineering interfaces and particles through the assembly of metal–phenolic networks
Frank Caruso
ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the 
Department of Chemical and Biomolecular Engineering, The University of Melbourne

The development of rapid and versatile coating strategies for interface and particle engineering is of immense scientific interest. Recently, we reported the rapid formation of thin films comprised of metal–phenolic networks (MPNs) on various substrates by simply mixing natural polyphenols and metal ions.1,2 This coating technique is substrate independent (covering organic, inorganic and biological substrates) and has been used for the assembly of capsules by coating particles and then removing the coated templates. It will be shown that a range of polyphenols and a library of metal ions are suitable in forming MPNs for film and capsule engineering. The MPN films and capsules are stable at physiological pH but degrade at acidic pH, making them of interest for intracellular release of therapeutics. By altering the metal ions, different functions can be incorporated in the MPN materials, ranging from fluorescence to MRI and catalytic capabilities. Furthermore, synthetic polymer-phenol conjugates have been used as building materials for control over the biofouling properties of the MPN materials.3 The ease and scalability of the assembly process, combined with pH responsiveness, negligible cytotoxicity and tunable properties, provides a new avenue for functional interface engineering, and makes these MPNs potential candidates for biomedical and environmental applications.

1. Ejima, H.; Richardson, J. J.; Liang, K.; Best, J. P.; van Koeverden, M. P.; Such, G. K.; Cui, J.; Caruso, F. Science 2013, 341, 154.
2. Guo, J.; Ping, Y.; Ejima, H.; Alt, K.; Meissner, M.; Richardson, J. J.; Yan, Y.; Peter, K.; Elverfeldt, D. v.; Hagemeyer, C. E.; Caruso, F. Angew. Chem. Int. Ed. 2014, 53, 5546.
3. Ju, Y.; Cui, J.; Müllner, M.; Suma, T.; Hu, M.; Caruso, F. Biomacromolecules DOI: 10.1021/bm5017139.

  • DNA Nanostructures and their Applications
Sung Ha Park
Department of Physics and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT),
Sungkyunkwan University, Suwon 440-746, Korea

Nanobiotechnology has evolved into a unique interdisciplinary field involving physics,  materials science, chemistry, biology, computer science, and multiple engineering fields. Likewise, DNA nanotechnology is a quickly developing field with essentially no overwhelming technical difficulties inhibiting progress toward designing and fabricating new shapes of DNA nanostructures in all dimensions. In this field, researchers create artificial DNA sequences to self-assemble into target molecular nanostructures. The well understood Watson–Crick base-pairing rules are used to encode assembly instructions directly into the DNA molecules which provide basic building blocks for constructing functionalized nanostructures with two major features: self-assembly and self-alignment. In this talk, we present on self-assembled various DNA nanostructures. 1D and 2D periodically patterned nanostructures utilizing several distinct DNA motifs such as cross tiles, double crossover tiles as well as single-stranded tiles will be discussed with unique design schemes and characteristics. We also discuss new development of DNA fabrication methods such as Angle Control Scheme, Surface Assisted Growth and Dry & Wet Method. At the end of the talk, we address applications of DNA nanotechnology which will show feasibility to construct various physical devices and biological/chemical sensors with DNA nanostructures.

  • Anisotropic colloids via stimulated dewetting
Stefano Sacanna
Department of Chemistry, New York University

Shape a
nd chemical anisotropy play fundamental roles at the colloidal scale, as they can govern the autonomous organization of particles into precise hierarchical structures and ultimately into a desired new material. In this talk, I will present an emulsion-based methodology to design and mass-produce building blocks featuring anisotropic shapes and interactions. The method is based on chemically reactive emulsion droplets that can be polymerized, reshaped and functionalized in bulk. I will further highlight how we use these building blocks to develop heuristic rules to create self-assembling colloidal systems.

  • Self-assembly of colloids with directional and specific interactions
David J Pine
Department of Physics, New York University

The self-assembly of colloids has been largely limited to spheres and rods with non-specific interactions and no directionality other than that imparted by a rod. Recently a variety of new colloidal particles have been introduced, including particles with sticky patches, dimples and cavities, and other complex shapes, that assemble into spectrum of new structures. Here we focus on the development of DNA-coated particles with highly specific, programmable, and thermally reversible interactions provides unprecedented control over particle assembly. Of particular interest is the ability to assemble colloidal particles made from different materials, including polymers, inorganics, and metals, into complex hybrid structures with programmed particle placement. A key recent development is the fabrication of DNA coatings that allow particles to bind and roll so that they can avoid kinetic traps and anneal into structures that minimize the free energy.

  • Continuous Generation of Bijel Microparticles, Fibers and Films Using Solvent Transfer-Induced Phase Separation (STRIPS)
Martin F. Haase, Nima Sharifi-Mood, Kathleen J. Stebe, Daeyeon Lee
Department of Chemical and Biomolecular Engineering, University of Pennsylvania

Bicontinuous interfacially jammed emulsions (Bijels) are novel soft materials with potential applications in areas ranging from healthcare, cosmetics, and food to energy and diverse chemical technologies. However, their fabrication is currently limited to only two pairs of immiscible liquids with narrow temperature windows for their formation. In such systems, typical bicontinuous domain sizes are in the range of tens of micrometers, and fabrication is inefficient due to its batch-wise nature and expensive starting materials. We explore the formation of bijels by mass transfer induced ternary liquid-liquid phase separation. The use of commercially available silica nanoparticles and ionic surfactants allows us to continuously form bijel fibers and membranes with controllable morphologies and domain sizes down to only a few hundreds of nanometers. We study the dependence of fiber morphology on different control parameters such as particle and surfactant concentration. Confocal and electron microscopy reveal hierarchical fiber architectures remarkably similar to polymer membranes formed via non-solvent induced phase inversion. However, unlike their polymeric counterparts, bijel fibers remain entirely liquid throughout their volume. This unique feature combined with the hierarchical morphology opens avenues to new applications such as bijel microfluidics or interfacial catalysis.

  • Nano-gap Enhanced Raman Scattering(NERS) controlled by DNA 
Yung Doug Suh
Lab. for Advanced Molecular Probing (LAMP), Research Center for Convergence Nanobiotechnology, Korea Research Institute of Chemical Technology (KRICT) , Yuseong P.O. Box 107, DaeJeon 305-600, Korea,
& School of Chemical Engineering, SungKyunKwan University (SKKU),  Suwon 440-746, Korea.

Since smSERS (single molecule Surface-Enhanced Raman Scattering) was independently reported by S. Nie group and K. Kneipp group in 1997 [1][2], tremendous amount of interest has been shown to this field because Raman spectroscopy can provide molecular fingerprint together with multiplexing capability in bioassay. Regarding to the origin of this smSERS phenomena, so called “SERS hot spot”, Nie group argued sharp edges in nanostructure, such as corners of a silver nanorod or even of a single nanoparticle, can play as a hot spot of smSERS, while Kneipp group argued they could observe smSERS signal only from colloidal aggregation in solution. Later on, Brus group and others showed that SERS hot spots, formed at the junction of two nanoparticles, likely play a major role in smSERS [3][4]. Theoretical calculations also support that SERS electromagnetic enhancement factors can approach up to ~1011 when inter-particle spacing reaches down to a few nanometer or less at the junction between two nanoparticle pair. However, formation of these smSERS-active nanostructures with a nano-gap at the SERS hot-spot junction, mostly dimer or colloidal aggregation of Ag or Au nanoparticles adsorbed with Raman active molecules (e.g., Rhodamine 6G), is a random process driven by salt-induced non-specific aggregation. This fact has been a main hurdle for smSERS toward advanced applications.[5]
Based on the idea that controlling this nano-gap between two noble metal nanoparticles is the key to realize reliable smSERS, we have designed a gold-silver nano dumbbell (GSND) and Gold Nanobridged Nanogap Particles (Au-NNP) to exhibit Nano-gap Enhanced Raman Scattering (NERS) controlled by DNA. As for GSND, two gold nano particles with different sizes were linked to each other by double helix DNA (30mer), with a single Raman dye molecule at the center position, to fix the two at a known gap distance (~10 nm). Then we narrowed the gap down to < 1 nm by standard silver staining method to endow the GSND with single molecule sensitivity. We have successfully detected smSERS signals, as well as typical single molecular blinking and polarization behaviors, from each GSNDs by Nano Raman spectroscopy at the single particle level [6-9]. As for Au-NNP, hollow spherical gap (~1 nm) between the gold core and gold shell can be precisely loaded with quantifiable amounts of Raman dyes labeled on DNA backbone which is anchored at the gold core and then covered by gold shell [10]. I will discuss several applications and variations of this Au-NNP including multiplexing Raman imaging of a single live cell.

[1] S. Nie and S.R. Emory, Science 275, 1102 (1997).
[2] K. Kneipp, Y. Wang, H. Kneipp, L.T. Perelman, I. Itzkan, R.R. Dasari, and M.S. Feld, Phys. Rev. Lett. 78, 1667 (1997).
[3] A.M. Michaels, M. Nirmal, and L.E. Brus, J. Am. Chem. Soc. 121, 9932 (1999).
[4] Y.D. Suh, G.K. Schenter, L. Zhu, and H.P. Lu, Ultramicroscopy 97, 89 (2003).
[5] H. Lee, S.M. Jin, H.M. Kim, and Y.D. Suh, Phys.Chem.Chem.Phys. 15, 5276 (2013).
[6] D. Lim, K.-S. Jeon, H.M. Kim, J.-M. Nam, and Y.D. Suh, Nature Materials 9, 60 (2010)
[7] J.-H. Lee, J.-M. Nam, K.-S. Jeon, D.-K. Lim, H. Kim, S. Kwon, H. Lee, Y.D. Suh, ACS Nano, 11, 9574 (2012)
[8] H. Lee, J.-H. Lee, S.M. Jin, Y.D. Suh, and J.-M. Nam, Nano Letters, 13, 6113 (2013)
[9] H. Lee, G.-H. Kim, J.-H. Lee, N.H. Kim, J.-M. Nam, and Y.D. Suh, Nano Letters, 15, 4628 (2015)
[10] D. Lim, K.-S. Jeon, J.H. Hwang, H.Y. Kim, S.H. Kwon, Y.D. Suh, and J.-M. Nam, Nature Nanotechnology 6, 452 (2011).

  • Self-assembly, trapping and manipulation of nonmagnetic microobjects with magnetic fields.
Bartosz A. Grzybowski
Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST)

Magnetic fields can manipulate non-magnetic/diamagnetic objects provided these objects are immersed in a medium of significantly higher magnetic susceptibility (e.g. solution of a paramagnetic salt or suspension of magnetic nanoparticles). Besides levitating a frog (for which an Ig-Nobel was once given to a future Nobel laureate), this phenomenon has been used in the assembly of macroscopic components as well as formation of colloidal arrays of various compositions. Along these lines, the first part of my talk will focus on the use of micropatterned static magnetic fields to drive formation of both mono-component and multi-component colloidal arrays, colloidal molecules, three-dimensional assemblies, and even arrays of bacteria and colloid-bacteria hybrids. These assemblies can comprise up to hundreds of millions of regularly positioned components. In the second part of the talk, I will focus on using magnetic fields to trap and manipulate individual non-magnetic microobjects. In the system we have recently developed, the microobjects (colloids or live cells) are immersed in a high-susceptibility solution (HoNO3 or Fe3O4/dextran nanoparticles, respectively) subject to a uniform magnetic field (~ 20 mT) produced by an external electromagnet. A sharp coaxial “pen” comprising tungsten core surrounded by a layer of Ni/Fe supermalloy is the working element of the system – when the external field is on, the pen creates a local minimum in the magnetic fluid beneath its tip, thus creating a trap for nonmagnetic objects; when the external filed is off, the trap vanishes. What is remarkable about this trapping mode is that the strength of the trap can be regulated by the electromagnet’s field, and its shape, by the cross-section of the magnetic pen. Capitalizing on these advantages, I will show how to address not only individual colloids or living cells, but also create traps with which entire colloidal formations (e.g., lines of particles) can be manipulated or traps in which colloidal clusters can be controllably crystallized. Many of the capabilities of our electromagnetic traps cannot be realized with optical trapping approaches.

Source literature: A.F. Demirörs, P.P. Pillai, B. Kowalczyk & B.A. Grzybowski* Assembly of two- and three-dimensional colloidal structures in virtual magnetic molds Nature 503, 99-103 (2013)

Daegu EXCO

Daegu EXCO