Bulletin of the American Physical Society
APS March Meeting 2010
Volume 55, Number 2
Monday–Friday, March 15–19, 2010; Portland, Oregon
Session X30: Bionanotechnology |
Hide Abstracts |
Sponsoring Units: FIAP Chair: Raghuveer Parthasarathy, University of Oregon Room: D139 |
Thursday, March 18, 2010 2:30PM - 2:42PM |
X30.00001: Quantitative Analysis of Multivalent Ligand Presentation on Gold Glyconanoparticles and Their Effects on Protein Binding Xin Wang, Olof Ramstr\"om, Mingdi Yan Bio-functionalized nanomaterials, which combine functions of biological ligands and unique properties of nano-sized building blocks, have exhibited increased potential applications in biosensing, therapeutics, and diagnostics. Glyconanoparitcles carrying a monolayer of carbohydrate ligands on nanoparticles provide an excellent platform for sensitive protein recognitions. Using Au nanoparticles as the scaffold, multivalent interactions between glycan ligands and proteins have been demonstrated. However, quantitative analysis especially the binding affinity of the resulting glyconanoparticles is challenging to determine. Here we present a new characterization technique, based on fluorescent competition binding assays, for measuring dissociation constants for glyconanoparticles-protein interactions. Au nanoparticles coupled with a series of un-derivatized carbohydrates were prepared by a photocoupling chemistry. Dramatic binding affinity enhancement was observed due to the high ligand density on nanoparticles, which was highly relevant to ligand display, controlled by the linker type, chain length, ligand size and density. [Preview Abstract] |
Thursday, March 18, 2010 2:42PM - 2:54PM |
X30.00002: Polyurethane nanoparticles as support for peroxidase immobilization and electrochemical detection of dopamine T\^ania Creczynski-Pasa, Maur\'Icia Fritzen-Garcia, In\^es Oliveira, Betina Zanetti-Ramos, Orlando Fatibello-Filho, Valdir Soldi, Andr\'e Pasa Two different carbon paste electrodes were constructed by the immobilization of peroxidase extracted from the pine kernel homogenate (I) or purified HRP (II) on pegylated polyurethane nanoparticles for dopamine detection. The polyurethane nanoparticles were characterized by AFM and DLS (260nm) and, showed good potential as a support material for enzyme immobilization. The best analytical response was obtained for the electrodes containing 2.5 U of peroxidase mg$^{-1}$ of carbon paste (I) and 0.25 U of HRP mg$^{-1}$ of carbon paste (II). The analytical curves were linear for dopamine from 9.9$\times $10$^{-5}$ to 1.6$\times $10$^{-3}$ mol L$^{-1}$ with a limit detection of 9.0$\times $10$^{-6}$ mol L$^{-1}$ for electrode I and 1.7$\times $10$^{-5}$ to 1.9$\times $10$^{-3}$ mol L$^{-1}$ with a limit detection of 2.0$\times $10$^{-6}$ mol L$^{-1}$ for electrode II. The recoveries of dopamine from pharmaceutical are in agreement with the official method. [Preview Abstract] |
Thursday, March 18, 2010 2:54PM - 3:06PM |
X30.00003: ABSTRACT WITHDRAWN |
Thursday, March 18, 2010 3:06PM - 3:18PM |
X30.00004: Hybrid protein-quantum dot nanoscale structures for biosensing and photovoltaics Mark Griep, Donald Lueking, Ray Mackay, Govind Mallick, Shashi Karna, Craig Friedrich Utilizing the direct energy transfer mechanism existing between semiconductor quantum dots (QD) and the hydrogen ion protein pump bacteriorhodopsin (bR), a multi-functional bioelectronics platform is demonstrated. Fluorescence resonance energy transfer (FRET) coupled QD-bR systems have been proven in both aqueous and dried film states, allowing for the vast QD optical absorbance range to directly contribute energy to the bR proton pumping sequence. A nanoscale deposition technique was employed to construct hybrid QD-bR electrodes capable of harnessing the FRET phenomena and enhancing the bR electrical output by nearly 300{\%}. A biosensing prototype system was created where the target molecule disrupts the QD-bR FRET relationship and is signaled by an altered bR electrical output. With an integrated TiO$_{2}$ electron generating substrate, the QD-bR hybrid functions as a sensitizer in a thin film bio solar cell design. [Preview Abstract] |
Thursday, March 18, 2010 3:18PM - 3:30PM |
X30.00005: Dehydration resistance of liposomes containing trehalose glycolipids Kendra Nyberg, Morgan Goulding, Raghuveer Parthasarathy The pathogen, \textit{Mycobacterium tuberculosis}, has an unusual outer membrane containing trehalose glycolipids that may contribute to its ability to survive freezing and dehydration. Based on our recent discovery that trehalose glycolipids confer dehydration resistance to supported lipid monolayers (\textit{Biophys. J.} \textbf{94:} 4718-4724 (2008); \textit{Langmuir} \textbf{25:} 5193-5198, (2009)), we hypothesized that liposomes containing synthetic trehalose glycolipids may be dehydration-resistant as well. To test this, we measured the leakage of encapsulated fluorophores and larger macromolecular cargo from such liposomes subject to freeze drying. Both leakage assays and size measurements show that the liposomes are dehydration-resistant. In addition to demonstrating a possibly technologically useful encapsulation platform, our results corroborate the view that encapsulation in a trehalose-glycolipid-rich membrane is a biophysically viable route to protection of mycobacteria from environmental stresses. [Preview Abstract] |
Thursday, March 18, 2010 3:30PM - 3:42PM |
X30.00006: Nano-Engineering Biocompatibility of Implant Surfaces for Enhanced Biointegration Renat Sabirianov, Alexander Rubinstein, Fereydoon Namavar This paper is part of continuing efforts to explain and determine the molecular mechanisms of enhanced cell adhesion and growth that we observed for our engineered nanocrystalline coatings. We performed the first-principles quantum-mechanical calculations of the nanocrystallite of the nanostructured ZrO$_{2}$. We show that contrary to the smooth surface, the calculated charge density and the electrostatic potential vary rather significantly on the topological features of nanostructured ZrO$_{2}$ surface. Based on our findings for ZrO$_{2}$ and the concept of electrostatic and steric complementarity which have been found very successful in analysis of protein-protein interactions, we propose to extend these ideas to protein adhesion on inorganic implant. These concepts may also explain the enhanced adhesion of cells to the engineered nanostructured surfaces compared to conventional smooth surfaces. [Preview Abstract] |
Thursday, March 18, 2010 3:42PM - 3:54PM |
X30.00007: Effect of Carbon Nanotubes on Mammalian Cells Michelle Chen, Asma Ahmed, Melanie Black, Nicole Kawamoto, Jessica Lucas, Armie Pagala, Tram Pham, Sara Stankiewicz, Howard Chen Carbon Nanotubes possess extraordinary electrical, mechanical, and thermal properties. Research on applying the carbon nanotubes for ultrasensitive detection, disease diagnosis, and drug delivery is rapidly developing. While the fundamental and technological findings on carbon nanotubes show great promise, it is extremely important to investigate the effect of the carbon nanotubes on human health. In our experiments, we introduce purified carbon nanotubes in suspension to ovary cells cultured from Hamsters. These cells are chosen since they show robust morphological changes associated with cytotoxicity that can easily be observed under a light microscope. We will discuss the toxicity of carbon nanotubes by characterizing the cell morphology and viability as a function of time and the concentration of carbon nanotube suspension. [Preview Abstract] |
Thursday, March 18, 2010 3:54PM - 4:06PM |
X30.00008: Fast and sensitive detection of infectious agents using NMR-based sensors Hakho Lee, Tae-Jong Yoon, Huilin Shao, Ralph Weissleder Direct detection of pathogens is key in combating human infections, in identifying nosocomial sources, in surveying food chains and in biodefense. When abundant, bacterial specimen can often be diagnosed by microscopy. Difficulties arise when specimen are scant, the bacterial counts are low, or samples are in complex media such as tissues or blood. Here, we report a new simple nanoparticle-based platform that can be readily used to detect pathogens in native biological samples. In this approach, bacteria are targeted by magnetic nanoparticles, concentrated into a microfluidic chamber, and detected by a miniaturized nuclear magnetic resonance (NMR) system. When applied to diagnose tuberculosis in unprocessed sputum samples, the system demonstrated an extraordinary sensitivity, detecting 20 bacteria/ml in $<$ 30 min. This new detection platform could be an ideal point-of-care diagnostic tool, especially in resource-limited settings. [Preview Abstract] |
Thursday, March 18, 2010 4:06PM - 4:18PM |
X30.00009: Surface plasmon enhanced spectroscopic ellipsometry based sensor for studying bio-molecular interaction Rakesh Moirangthem, Yia-Chung Chang, Shih-Hsin Hsu, Pei-Kuen Wei We investigate bio-molecular interaction using rotating analyzer spectroscopic ellipsometry integrated with prism and flow cell. By recording the ellipsometry data in terms of relative change in $\psi $, $\Delta $ as sensor signal we can observe the plasmonic response on the gold thin film with aqueous medium having different refractive index or the existence of a dielectric layer on the surface. We observed larger spectral shift of the features in $\psi $ and $\Delta $ versus the change of refractive index of the ambient medium as observed in conventional SPR system. Our simple experimental setup has an index of resolution of the order of 1.54$\times $10-6 which is much better than previous reported values by using conventional SPR method based on angular detection or spectroscopic measurement. Such sensitivity with a very simple technique is almost comparable with that of the heterodyne detection which has complicated optical setup. This kind of characterization technique is non-destructive, label free and it has high sensitivity and sub-nanometer thickness resolution. Furthermore, investigation can be made in aqueous medium. [Preview Abstract] |
Thursday, March 18, 2010 4:18PM - 4:30PM |
X30.00010: Determining the Detection Speed Limits of Nanobiosensors Matthew Leyden, Canan Schuman, Josh Kevek, Ethan Minot Nanoscale field-effect transistor (FET) biosensors are a promising candidate for fast, label-free, multiplexed detection of protein biomarkers in blood and other liquids. The fundamental limits of nanobiosensor detection speed have been explored in recent theoretical investigations. To realize these fundamental limits, the surface area where protein binding occurs must be shrunk to nanoscale dimensions. Our experiments test these predictions by studying the adsorption kinetics of proteins delivered to a carbon nanotube FET biosensor via a microfluidic channel. We demonstrate that protein flux has a linear dependence on protein concentration and show that detection times can be improved by shrinking the binding area of the sensor. [Preview Abstract] |
Thursday, March 18, 2010 4:30PM - 4:42PM |
X30.00011: Label-free detection of DNA hybridization using InAs $\mu $-Hall sensors Khaled Aledealat, S. Hira, K. Chen, G.F. Strouse, P.B. Chase, P. Xiong, S. von Molnar, G. Mihajlovic, M. Field, G. Sullivan We present results on label-free detection of DNA hybridization using InAs $\mu $-Hall sensors. The $\mu $-Hall sensor consisted of six 1-$\mu $m Hall crosses defined on an InAs quantum well substrate. The sensor was then covered with sputter-deposited SiO$_{2}$ and Au pads were patterned on top of some of the Hall crosses. Thiolated ssDNA strands that are complementary to one end of the target ssDNA were assembled on the Au pads and the rest of the device platform was passivated with PEG-silane. Biotinylated and fluorescently-tagged complementary ssDNA to the other end of the target ssDNA were labeled with commercial streptavidin-coated 350 nm superparamagnetic beads. Labeled ssDNA were found to assemble selectively onto the Au pads after mixing with the target ssDNA, indicating successful hybridization of the three ssDNA sequences. The presence of the assembled beads was successfully detected via the Hall sensor and confirmed using laser scanning confocal microscopy. This work was supported by NIH NIGMS GM079592. [Preview Abstract] |
Thursday, March 18, 2010 4:42PM - 4:54PM |
X30.00012: Label-free cancer biomarker detection using multiplexed silicon nanoribbon bioFETs Aleksandar Vacic, Eric Stern, Nitin Rajan, Jason Criscione, Tarek Fahmy, Mark Reed In this work we investigate label-free detection of cancer biomarkers using multiplexed silicon nanoribbon field effect transistors. Prostate, PSA and breast cancer, CA 15-3, antigens are obtained from the whole blood using capture-release method. The sensor surface is modified using 3-aminopropyltrietoxysilane, followed by appropriate antibody attachment. Since, asymptotic saturation value of sensor response is weakly dependent on analyte concentration for reversible reactions with low dissociation constant, such as this one, we use normalized initial rate as a parameter for device response calibration. We show that device response is linear in the region of clinically relevant biomarker concentrations. [Preview Abstract] |
Thursday, March 18, 2010 4:54PM - 5:06PM |
X30.00013: Low Frequency noise of nanowire bioFETs Nitin Rajan, Jin Chen, David Routenberg, Mark Reed In this study we characterize the low frequency noise of top-down fabricated silicon nanowire FETs with exposed channels used as biological sensors. Understanding their low frequency noise behavior is important because signal-to-noise ratio limits the sensitivity of these devices when attempting to detect low analyte concentrations. Using noise spectroscopy we quantitatively demonstrate that a wet orientation dependent etch (ODE) using tetramethylammonium hydroxide yields a lower surface state density and thus better noise performance that common plasma-based etch processes. To thoroughly characterize and accurately model the noise of fabricated silicon nanowires using the wet ODE, we carry out 1/f noise measurements from subthreshold to strong inversion as well as noise measurements at different temperatures. We observe an increase in the noise amplitude at lower temperatures, the increase being more pronounced in the subthreshold region. We also observe a change in the noise profile, indicating a change in the dominant mechanism giving rise to 1/f noise, as the temperature is lowered. [Preview Abstract] |
Thursday, March 18, 2010 5:06PM - 5:18PM |
X30.00014: Polymer nanopillar arrays via NIL for optical, photovoltaic and sensing applications Binod Rizal, Thomas Hogan, Christina Gennaoui, Daniel Virgil, Svet Simidjiyski, T.C. Chiles, M.J. Naughton We have used nanoimprint lithography to fabricate high fidelity replicants of silicon nanopillar arrays in polymer form, using PDMS molds to create SU-8 and siloxane spin-on-glass structures. Typical nanopillar dimensions are 50-200 nm diameter and 1-2 $\mu $m height, with pitches between 0.8 and 1.5 $\mu $m. Both substrated and free-standing films have been produced. Forming the structural cores of nanocoaxial electrodes, the polymer nanopillars can facilitate a flexible platform for a wide variety of nanoscale applications, including optical waveguiding, solar cells, and multiplexed biochemical sensing. We will report on each. [Preview Abstract] |
Thursday, March 18, 2010 5:18PM - 5:30PM |
X30.00015: ABSTRACT WITHDRAWN |
Thursday, March 18, 2010 5:30PM - 5:42PM |
X30.00016: Carbon nanotube monolayer patterns for modulating stem cell behavior Sung Young Park, Ki-Bum Lee, Seunghun Hong Nanostructures and nanomaterials intrinsically can interact with biological systems at the fundamental molecular levels with high specificity, which has held great potential for developing methods of controlling cell behaviors such as adhesion, proliferation, and differentiation. For instance, carbon nanotubes (CNTs), as extracellular scaffolds, have been used to guide neural cell growth and regulate cell polarity. However, in order to harness the potential of nanomaterials as artificial scaffolds, there is a clear need to develop methods of patterning nanomaterials over large surfaces with high precision and maintaining biocompatibility of patterned nanostructures. Herein, we report a novel method to regulate stem cell behaviors by using of combinatorial CNT patterns with different shapes and sizes in an effective way. Importantly, the SCs exhibited preferential growth on CNT patterns, and the CNT monolayer patterns did not show cytotoxicity during the long-term cell culture. These results clearly show that CNT monolayer patterns have enormous potentials as a platform for basic research and applications in stem cell tissue-engineering. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700