California NanoSystems Institute
CNSI
Text Size: A A A A

March 21, 2005

Ed Kosower
University of Tel-Aviv, Israel
Fiberoptic IR Spectroscopy: Surface Enhancement on Planar AgX and Other Discoveries
Abstract:
(From J.Phys.Chem.B 2004 108, 12633-12636, 12873-12876)

We have discovered surface-enhanced infrared absorption (SEIRA) on a planar silver halide surface, the first time this effect has been observed on a non-metallic substrate. In addition, the fibers show tenfold spectral amplification due to the increased coupling of evanescent waves to the samples on the surface. A special cell containing the planar silver halide fiber permits deposition of small quantities of solution followed by slow evaporation of the water with dry nitrogen and allows measurements to be made on much less than a monolayer of sample. The combination of easy access to the sample and high sensitivity promises many useful applications to biological, chemical and physical problems in the mesoscopic and nanoscopic domains.

Surface-enhanced infrared absorption (SEIRA), recently discovered for trypsin on a planar silver halide surface, is now demonstrated for the small organic molecule, p-nitrobenzoic acid (pNBA). Evaporation of pNBA solutions in acetonitrile yields the acid dimer (confirmed by the unique IR signature of carboxylic acid dimers). The absorption changes for pNBA with quantity exhibit two regimes: "enhanced" and "regular" A plot of absorbance versus quantity reveals how SEIRA changes with distance from the surface. The surface orientation of pNBA has the long and short axes (unit cell) parallel to the surface (packing density/carbonyl peaks). "Slice" spectra differentiate between surface pNBA and other layers. Most of the numerous previous reports on pNBA actually refer to the p-nitrobenzoate anion probably generated through reaction of surface silver oxide with the acid.

Newer work will also be discussed.

March 15, 2005

Michal Lipson
Cornell University


Streaming Video
  

Manipulating Light on a Chip Using Nanophotonic Structures
Abstract:

Photonics on chip could enable a platform for monolithic integration of optics and microelectronics for applications of optical interconnects in which high data streams are required in a small footprint. Recent results in Nanophotonics have shown the ability to guide, filter, bend and split light on Silicon chips using nano-size structures. In this talk I will review the challenges and achievement in the field of Nanophotonics and present our recent results. Using highly confined photonic structures we have demonstrated ultra-compact passive and active silicon photonic components with very low loss.

References:

Almeida, V. R., Barrios, C. A., Panepucci, R. R., Lipson, M., "All-Optical control of light on a Silicon chip", Nature, pp1081-1084 (Oct 2004)

Qianfan Xu, Vilson R. Almeida, Roberto R. Panepucci, and Michal Lipson, "Experimental demonstration of guiding and confining light in nanometer-size low-refractive-index material", Optics Letters 29, 1626 (July 2004)

March 08, 2005

Milan Mrksich
University of Chicago


Streaming Video
  

Engineering Active Interfaces Between Cells and Materials
Abstract:

This lecture will describe a chemical approach to integrating mammalian cells and electrical components. The strategy is based on self-assembled monolayers of alkanethiolates on gold that are modified with peptide ligands which promote cell adhesion. The monolayers are then engineered with electroactive moieties such that application of an electrical potential to the gold film results in modulation of the activities of immobilized ligands. The lecture will describe several strategies for creating functional interfaces between cells and electronics, and will address the opportunities for applying these strategies to creating hybrid devices comprising electrical and cellular components.

References:

Self-Assembled Monolayers That Transduce Enzymatic Activities to Electrical Signals. W.S. Yeo and M. Mrksich. Angew. Chem. Int. Ed., 2003, 42(27), 3121-3124 [PDF]

Electroactive Substrates that Reveal Aldehyde Groups for Bio-Immobilization. W.S. Yeo and M. Mrksich. Adv. Mater., 2004, 16, 1352-1356. [PDF]

March 01, 2005

Allan Hoffman
University of Washington


Streaming Video
  

Smart Polymer Switches in Nanotechnology and Biotechnology
Abstract:

We have been combining stimuli-responsive or "smart" polymers with biomolecules to yield nano-scale particles that can (a) reversibly "switch" the solubility of the polymer-biomolecule conjugate, (b) reversibly "switch" protein recognition processes on and off by blocking and unblocking the protein active site with the smart polymer, or (c) "switch" on transport across intracellular vesicle membranes as the drop in pH within the vesicle causes the smart polymer to disrupt the lipid membrane and escape the vesicle. Each of these molecular actions is caused by a change in the polymer solubility that is stimulated by a small change in a local environmental condition, eg, by a change in temperature, pH or wavelength of light. This talk will describe a number of diverse applications of these smart polymer biomolecule systems in biotechnology and nanotechnology, including immunodiagnostics in microfluidic devices, affinity separations, enzyme bioprocesses, and drug delivery.

References:

Selected references for talk of Allan Hoffman, March 1, 2005

Phase Separation Systems

Hoffman, A.S., "Applications of Thermally Reversible Polymers and Hydrogels in Therapeutics and Diagnostics", J. Contr. Rel., 6, 297-305 (1987).

Chen, G.H., and A.S. Hoffman, "Graft copolymer compositions that exhibit temperature-induced transitions over a wide range of pH", Nature, 373, 49-52 (1995)

Z. Ding, G. Chen and A.S. Hoffman, "Properties of PolyNIPAAm-Trypsin Conjugates", J. Biomed. Mater. Res. , 39, 498-505 (1998)

R.B. Fong, Z. Ding, C.J. Long, A.S. Hoffman and P.S. Stayton, "Thermoprecipitation of Streptavidin via Oligonucleotide-Mediated Self-Assembly with Poly(NIPAAm)", Bioconj. Chem. 10, 720-725 (1999)

A.S. Hoffman, et al., "Really Smart Bioconjugates of Smart Polymers and Receptor Proteins", J. Biomed. Mater. Res., 52, 577-586 (2000)

Controlling the Active Site of a Protein

Stayton, P.S., T. Shimoboji, C. Long, A. Chilkoti, G. Chen, J.M. Harris and A.S. Hoffman, "Control of protein-ligand recognition using a stimuli-responsive polymer", Nature, 378, 472-474 (1995)

V. Bulmus, Z. Ding, C.J. Long, P.S. Stayton and A.S. Hoffman, "Design, Synthesis and Site-Specific Conjugation of a pH- and Temperature-Sensitive Polymer to Streptavidin for pH-Controlled Binding and Triggered Release of Biotin", Bioconj. Chem., 11, 78-83 (1999)

Z. Ding, T. Shimoboji, P.S. Stayton, A.S. Hoffman, "A Smart Polymer Shield that Controls the Binding of Different Size Biotinylated Proteins to Streptavidin", Nature, 411, 59 - 62 (2001)

T. Shimoboji, E. Larenas, T. Fowler, S. Kulkarni, A.S. Hoffman and P.S. Stayton, "Photoresponsive polymer-enzyme switches", PNAS, 99, 16592-6 (2002)

Microfluidic Devices

N. Malmstadt, P. Yager, A.S. Hoffman, and P.S. Stayton, "A Smart Microfluidic Affinity Chromatography Matrix Composed of Poly( N-isopropylacrylamide)-Coated Beads", Anal Chem, 75, 2943-2949 (2003) (Accelerated Article)

N. Malmstadt, A.S. Hoffman and P.S. Stayton, "Smart Mobile Affinity Matrix for Microfluidic Immunoassays", Lab Chip, 4, 412-415 (2004)

Intracellular Drug Delivery

N. Murthy, P.S. Stayton and A.S. Hoffman, "The Design and Synthesis of Polymers for Eukaryotic Membrane Disruption", J. Contr. Rel., 61, 137-143 (1999)

C.Y. Cheung, N. Murthy, P.S. Stayton and A.S. Hoffman, "A pH-sensitive Polymer that Enhances Cationic Lipid-Mediated Gene Transfer", Bioconj. Chem., 12, 906-910 (2001).

T.R. Kyriakides, C.Y. Cheung, N. Murthy, P. Bornstein, P.S. Stayton, and A.S. Hoffman, "pH-Sens. Pols. that Enhance Intracellular Drug Delivery in vivo" , J. Contr. Rel., 78, 295-303 (2002).

C.A. Lackey, O.W. Press, A.S. Hoffman, and P.S. Stayton, "Uptake and Endosomal Release of a Targeted pH-Sensitive Polymer-Protein Complex",Bioconj. Chem. 13, 996-1001 (2002)

N. Murthy, J. Campbell, N. Fausto, A.S. Hoffman and P.S. Stayton, "Cytoplasmic Delivery from Endosomes of Drugs that are Conjugated or Complexed to Membrane-disruptive Polymers via pH-degradable Linkages" Bioconj. Chem. (2003), 14, 412-419

Biography:

Professor Hoffman studied at M.I.T., where he received B.S., M.S., and Sc.D. degrees in Chemical Engineering between 1953 and 1957. He taught on the faculty of M.I.T. Chemical Engineering Department for a total of ten years. He also spent four years in industry. Since 1970 he has been Professor of Bioengineering at the University of Washington in Seattle, Washington.

Professor Hoffman has over 330 publications, several books and chapters, 21 patents and 6 patents pending. He is on the Editorial Boards of six scientific journals.

Some of his professional activities and awards have included:
  • Chairman, Gordon Conference on Biomaterials, 1977
  • President, Society for Biomaterials, 1983-1984
  • Clemson Award in Biomaterials, 1984
  • Two Controlled Release Society Awards to my students, 1990 and 1999
  • Board of Governors, Controlled Release Society, 1991-1994
  • Japanese Biomaterials Society Science Award, 1990
  • Founding Fellow of the American Inst. of Med.& Bioeng., 1992
  • FoundersÂ’ Award of the Society for Biomaterials, 2000

In December, 1992, his colleagues organized a symposium in Maui, Hawaii in honor of his 60th birthday. Ten years later, in December, 2002, his colleagues organized another symposium, this time in honor of his 70th birthday, and once again in Maui, Hawaii. Each symposium was well attended by over 120 scientists from around the world, and each resulted in Festschrifts, published as multiple issues of the Journal of Biomaterials Science, Polymer Edition. Each also resulted in publication of a Festschrift book containing a compilation of those published papers..

February 22, 2005

Alexander Balandin
UC Riverside


Streaming Video
  

Nano-Phonomics: From Concepts to Device Applications
Abstract:

Phonons, i.e. quanta of lattice vibrations, manifest themselves practically in all electrical, thermal and optical phenomena in semiconductors and other material systems. Reduction of the size of electronic devices below the acoustic phonon mean free path creates a new situation for the phonon propagation and interaction. From one side, it may complicate heat removal from downscaled devices, from the other side, it opens up an exciting opportunity for re-engineering phonon properties in nanostructured materials, thus achieving enhanced operation of nano-devices. In this talk I describe the fundamentals of a new sub-field of nanotechnology research – nano-phononics- focusing on how tuning of the phonon spectrum in nanostructures can lead to a reduction or enhancement of thermal conductivity, formation of the phonon stop-bands, changing the optical properties or suppression of the electron – phonon scattering rates. Our recent theoretical and experimental results on phonons in TMV viruses used as biological nano-templates for self-assembly of nanoelectronic circuits will also be discussed [1].

[1]. For more information on nano-phononics research, visit NDL at http://ndl.ee.ucr.edu

Phonon-Related References

[1]. A.A. Balandin and K.L. Wang, Phys. Rev. B, 58, 1544 (1998).
[2]. O.L. Lazarenkova and A.A. Balandin, Phys. Rev. B, 66, 245319 (2002).
[3] E.P. Pokatilov, D. Nika and A.A. Balandin, Appl. Phys. Lett., 85, 825 (2004).
[4]. V.A. Fonoberov and A.A. Balandin, phys. stat. solidi (b), 241, R67 (2004).

Biography:

Professor Balandin received his Diploma in Applied Physics and Mathematics from the Moscow Institute of Physics and Technology, Russia in 1991 and PhD degree in Electrical Engineering from the University of Notre Dame, USA in 1997. Professor Balandin is an author of more than 70 technical papers, 10 book chapters and one book. He is on editorial board of the Journal of Nanoscience and Nanotechnology. His research received the Office of Naval Research Young Investigator Award (2002), NSF Faculty Early CAREER Development Award (2001), US CRDF Young Investigator Award (1999), and Merrill Lynch Foundation Award (1998). Professor Balandin leads the Nano-Device Laboratory (NDL) at the Department of Electrical Engineering, UCR, which carries out theoretical and experimental research in the field of hybrid-bio-inorganic nanostructures and novel nanoelectronic devices. For more information on his research, visit his group’s website at http://ndl.ee.ucr.edu/

February 15, 2005

Tak Ning
IBM


Streaming Video
  

Nanotechnology Opportunities from a System Application Perspective
Abstract:

Nanotechnology is undoubtedly one of the most active and exciting area of research. With silicon CMOS, which is the backbone of all computing and communication systems, reaching its scaling limits, there is high hope and speculation that nanotechnology will come to the rescue. In this talk, we discuss nanotechnology from a system application perspective. We examine both the potential opportunities and challenges for nanotechnology in computing system and personal wireless system applications.

References:

Plenary Paper 2003 VLSI Tech Symp - Kyoto.pdf

2000 CICC Proceeding.pdf

Biography:

Tak H. Ning received his Ph. D. degree in physics from the University of Illinois at Urbana-Champaign in 1971. He joined IBM Thomas J. Watson Research Center in 1973. His early technical contributions were in understanding hot-electron effects and in advanced bipolar technology. From 1982 to 1991, he managed the silicon devices and technology department in IBM Research, contributing to and leading the research effort on CMOS, bipolar, DRAM, EEPROM and SOI. He was appointed an IBM Fellow in 1991. In recent years, he has focused his technical activities on understanding the limits of CMOS as well as the opportunities beyond CMOS. He received the 1989 IEEE Electron Devices Society J.J. Ebers Award and the 1991 IEEE Jack A. Morton Award. He is a member of the National Academy of Engineering, and a fellow of the IEEE and of the American Physical Society.

February 08, 2005

Kimberly Turner
UC Santa Barbara


Streaming Video
  

Nonlinear Mechanics Approaches to Micro and Nanoscale Sensing
Abstract:

MEMS and NEMS provide a novel and exciting medium where one can observe and utilize mathematical phenomena not often present in macro-scale systems. By understanding thoroughly the dynamics of resonant MEMS, we can not only predict device behavior to eliminate unwanted effects, but also use nonlinear effects to design better sensors and systems. In our work, we have utilized and exploited nonlinear effects in the design of micro and nano-scale resonant sensors. The design of a nonlinear, parametrically resonant mass/chemical sensor will be discussed in detail and experimental sensor data and noise analysis will be presented. This approach allows for significant sensitivity improvements over existing resonant mass sensors.

February 01, 2005

Jeff F. Miller
UCLA


Streaming Video
  

Engineering Molecular Recognition Using Diversity-Generating Retroelements
Abstract:

Viruses that infect bacteria (a.k.a. bacteriophage) are the most abundant replicating biological entities on the planet. These remarkable nanomachines have evolved myriad ways to subvert their bacterial hosts and multiply, and they provide a rich repository of useful biological mechanisms. We have recently discovered a family of "diversity-generating retroelements" (DGRs) that function to diversify DNA sequences and the proteins they encode. The prototype DGR was identified in a bacteriophage on the basis of its ability to generate variability in a viral receptor protein that specifies tropism for ligand molecules on host cells. Tropism switching is a template-dependent, reverse transcriptase-mediated process that introduces nucleotide substitutions at defined locations within a target gene. It is a cassette-based mechanism that is amenable to genetic engineering. Using the phage DGR sequence as a signature, we have identified homologous elements in numerous bacterial and bacteriophage genomes. In addition to their fundamental importance as naturally occurring agents of evolution, DGRs are of considerable interest as a result of their applications for generating vast amounts of targeted diversity for protein engineering. In the context of bacteriophage genomes, they may also allow the development of a new class of "dynamic" antibacterial agents able to keep pace with the development of antimicrobial resistance.

References:

Doulatov, S., Hodes, A., Dai, L., Madhana, N., Liu, M., Deora, R., Simons, R.W., Zimmerly, S. & J.F. Miller (2004) Tropism switching in Bordetella bacteriophage defines a family of diversity-generating retroelements. Nature: 431:476-481.

Liu, M., Deora, R., Doulatov, S.R., Gingery, M., Eiserling, F.A., Simons, R.W., Cotter, P.A., Parkhill, J. and J.F. Miller (2002) Reverse Transcriptase-Mediated Tropism Switching by Bordetella Bacteriophage. Science295: 2091-2094.

January 25, 2005

Hong-Wen Jiang
UCLA


Streaming Video
  

Spins in Semiconductor Nanostructures for Quantum Information Processing
Abstract:

In this talk I will give an introduction to the basic ideas of quantum computing and communications, and describe some mind-boggling applications.
I will provide an overview of the interdisciplinary research at UCLA to develop a basic building block, using electron spins, for the quantum information processing. I will present some breakthrough results of manipulation and detection of quantum states of individual spins in semiconductor nanostructures by the UCLA team.

References:

M. Xiao, I. Martin, E. Yablonovitch, and H. W. Jiang, "Electrical Detection of the Spin Resonance of a Single Electron in a Silicon Field-Effect Transistor", Nature 430, 435 (2004).

E. Yablonovitch, H. W. Jiang, H. Kosaka, H. Robinson, D. Sethu Rao, and T. Szkopek, "Optoelectronic Quantum Telecommunications Based on Spins in Semiconductors", Special Issue on Spintronics Technology, Proceedings of the IEEE, 91, 727 (2003).

January 18, 2005

Darrin Pochan
University of Delaware
Nanostructure Construction through Biomolecular and Biomimetic Self-Assembly
CANCELLED
January 11, 2005

Kathryn Uhrich
Rutgers University


Streaming Video
  

Nanoscale Amphiphilic Macromolecules: From sequestering low density lipoproteins to transporting drugs across cellular membranes
Abstract:

This talk will describe a unique twist on conventional approaches to drug delivery. The design and synthesis of amphiphilic star-like macromolecules (ASMs) will be discussed. These ASMs are water-soluble polymers with a highly branched, hydrophobic interior (core) and hydrophilic exterior (shell) to maintain physical properties characteristic of conventional micelles. Other design criteria include biocompatibility of the polymer and its components, as well as the ability to influence membrane permeability as a function of the polymer's amphiphilicity. Drug encapsulation and transport through various cell membranes is controlled by the amphiphilic nature of the ASMs, as is the presentation of cell-specific ligands.

References:

Tian, L; Yam, L; Zhou, N; Tat, H and Uhrich, KE " Amphiphilic Scorpion-like Macromolecules (AScMs): Design, Synthesis and Characterization", Macromolecules, 37 (2) 538-543 (2004).

Djordjevic, J; Michniak, B and Uhrich, KE "Amphiphilic Star-like Macromolecules as Novel Carriers for Topical Delivery of Nonsteroidal Anti-Inflammatory Drugs", AAPS Pharm. Sci., 5 (4) 256-267 (2003).