Bulletin of the American Physical Society
APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014; Denver, Colorado
Session Q45: Bionanotechnology and Applications of Polymers and Biomaterials |
Hide Abstracts |
Sponsoring Units: FIAP Room: Mile High Ballroom 4D |
Wednesday, March 5, 2014 2:30PM - 2:42PM |
Q45.00001: Electrochemical impedance spectroscopy for graphene surface modification and protein translocation through the chemically modified graphene nanopore Purushottam Tiwari, Yuping Shan, Xuewen Wang, Yesim Darici, Jin He The multilayer graphene surface has been modified using mercaptohexadecanoic acid (MHA) and 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-750] (DPPE-PEG750). The surface modifications are evaluated using electrochemical impedance spectroscopy (EIS). EIS measurements show the better graphene surface passivation with DPPE-PEG750 than with MHA. After modification with ferritin, the MHA modified surface shows greater charge transfer resistance (R$_{ct})$ change than DPPE-PEG750 modified surface. Based on these results the translocations of ferritin through modified graphene nanopore with diameter 5-20 nm are studied. The translocation is more successful through DPPE-PEG750 modified graphene nanopore. This concludes that that the attachment of ferritin to DPPE-PEG750 modified graphene nanopore is not significant compared to MHA modified pore for the ferritin translocation hindrance. These results nicely correlate with the EIS data for respective R$_{ct}$ change of ferritin modified surfaces. [Preview Abstract] |
Wednesday, March 5, 2014 2:42PM - 2:54PM |
Q45.00002: Preparation and characterization of functionalized single walled carbon nanotubes (fSWCNT)/ Hydroxyapatite (HAp)-Nylon hybridized composite biomaterial to study the mechanical properties Suraj Khanal, Theodora Leventouri, Hassan Mahfuz, Adam Rondinone Synthetic hydroxyapatite (HAp) bears poor mechanical properties that limit its applicability in orthopedics. We study the possibility of overcoming such limitations by incorporating functionalized single walled carbon nanotubes (fSWCNT) in a biocompatible/bioactive nano-composite. We present results from synthesis and characterization of samples prepared under different processing parameters. Ultra sonication method was to disperse functionalized single walled carbon nanotubes (fSWCNT) in HAp followed by a simple hot assorting method to incorporate with polymerized $\varepsilon $-caprolactam. The fracture toughness of the composite materials was tested in compliance with the ASTM D-5045 standard. We have found that while the fracture toughness strongly depends on the processing parameters, a value comparable to the one for cortical bone is achieved. Mechanical properties, electron microscopy and crystal structure properties of the composite materials will be discussed. [Preview Abstract] |
Wednesday, March 5, 2014 2:54PM - 3:06PM |
Q45.00003: Enzyme Entrapment in Polyaniline Biosensors Observed via Fluorescence Anisotropy and Antiquenching Louis Nemzer The entrapment of oxidoreductase enzymes within polyaniline polymer films by inducing hydrophobic collapse using phosphate buffered solution (PBS) has been shown to be a cost-effective method for fabricating organic biosensors. Here, we use fluorescence anisotropy measurements to verify enzyme immobilization and subsequent electron donation to the polymer matrix, both prerequisites for an effective biosensor. Specifically, we observe a three order of magnitude decrease in the ratio of the fluorescence to rotational lifetimes. The observed fluorescence antiquenching supports the previously proposed model that the polymer chain assumes a severely coiled conformation when exposed to PBS. We also find that this collapse is further aided by the enzyme itself. [Preview Abstract] |
Wednesday, March 5, 2014 3:06PM - 3:18PM |
Q45.00004: High throughput transfection of cells: nano-electroporation and mobile magnetic traps M. Howdyshell, D. Gallego-Perez, G. Vieira, V. Malkoc, L.J. Lee, R. Sooryakumar Injection of drugs or genes in vitro into cells is a critical technique for biomedical research; there are currently a number of techniques to perform such injections, but drawbacks include lack of control over dosage rates and sustained cell viability, as well as inability to inject into many cells in parallel. We have previously demonstrated a magnetically actuated nano-channel electroporation technique that multiplexes simultaneous transfection of biomolecules into cells by combining an array of remotely operated micro-magnetic traps with a nano-channel electroporation device. This device allows us to control the dosage delivered to each individual cell and reduce cell death during the experiment. The magnetic traps enable precise positioning of magnetically labeled cells and subsequent relocation of the cells for downstream processing. With this integrated approach, the number of cells transfected simultaneously has been increased nearly tenfold. In the current work, we present recent experiments with different types of cells as well as new multiplexed nano-electroporation device designs that are more high-throughput to streamline the parallel injection process, allowing the device to be implemented for a wider variety of applications. [Preview Abstract] |
Wednesday, March 5, 2014 3:18PM - 3:30PM |
Q45.00005: Intracellular distribution of Fe$_{3}$O$_{4}$ nanoparticles in both human and mouse cells Maheshika Palihawadana Arachchige, Suvra Laha, Amulya Rajagopal, Sanjana Kulkarni, Shuo Wang, Amanda Flack, Chunying Li, Bhanu Jena, Gavin Lawes In recent years there has been an increasing interest in developing Fe$_{3}$O$_{4}$ nanoparticles for biomedical applications including targeted drug delivery and magnetic resonance imaging. Understanding of the intracellular distribution of these nanoparticles is crucial when considering these nanoparticles for specific applications. We have synthesized Fe$_{3}$O$_{4}$ nanoparticles having average size of 14 nm using a co-precipitation technique, which were coated with dextran. We studied the structural and morphological characteristics of the nanoparticles using x-ray diffraction, electron microscopy, dynamic light scattering, and zeta potential measurements. We also characterized the magnetic properties of the nanoparticles. In order to investigate the intracellular distribution of these Fe$_{3}$O$_{4}$ nanoparticles, we functionalized the dextran coated Fe$_{3}$O$_{4}$ nanoparticles with a fluorescent dye, Fluorescein isothiocyanate (FITC), and cultured them with both mouse insulinoma MIN 6 cells and human pancreatic MIA PaCa 2 cells. Using optical microscope we investigated the intracellular distribution of the nanoparticles and the effects on cell growth. [Preview Abstract] |
Wednesday, March 5, 2014 3:30PM - 3:42PM |
Q45.00006: Cell Studies of BiFeO$_{3}$ nanoparticles for multimodal imaging Suvra Laha, Maheshika Palihawadana Arachchige, Amanda Flack, Sagar Paudel, Jaipal Singh, Amulya Rajagopal, Sanjana Kulkarni, Michael Synder, Joe Rakowski, Xuequn Chen, Bhanu Jena, Gavin Lawes There is considerable interest in using nanoparticles as contrast agents to improve diagnostic imaging. BiFeO$_{3}$ nanoparticles may be particularly interesting as multimodal contrast agents for both magnetic resonance imaging and x-ray imaging because these combine a large magnetic susceptibility with high atomic mass constituents. We synthesized BiFeO$_{3}$ nanoparticles using a chemical co-precipitation technique. We measured the structural and morphological characteristics of these nanoparticles using x-ray diffraction, electron microscopy, dynamic light scattering, and zeta potential, and probed the magnetic properties through both ac and dc magnetization studies. In order to investigate the cytotoxicity and intracellular distribution of these BiFeO$_{3}$ nanoparticles, we cultured them with mouse insulinoma MIN 6 cells and used optical microscopy to investigate the distribution and cell growth. We discuss the cytotoxicity of these nanoparticles, which will be crucial factor for determining possible biomedical applications together with a discussion of the cellular distribution of these nanoparticles. [Preview Abstract] |
Wednesday, March 5, 2014 3:42PM - 3:54PM |
Q45.00007: Metallic Glass Wire Based Localization of Kinesin/Microtubule Bio-molecular Motility System K. Kim, A. Sikora, S. Yaginuma, K.S. Nakayama, H. Nakazawa, M. Umetsu, W. Hwang, W. Teizer We report electrophoretic accumulation of microtubules along metallic glass (Pd$_{42.5}$Cu$_{30}$Ni$_{7.5}$P$_{20}$) wires free-standing in solution. Microtubules are dynamic cytoskeletal filaments. Kinesin is a cytoskeletal motor protein. Functions of these bio-molecules are central to various dynamic cellular processes. Functional artificial organization of bio-molecules is a prerequisite for transferring their native functions into device applications. Fluorescence microscopy at the individual-microtubule level reveals microtubules aligning along the wire axis during the electrophoretic migration. Casein-treated electrodes are effective for releasing trapped microtubules upon removal of the external field. Furthermore, we demonstrate gliding motion of microtubules on kinesin-treated metallic glass wires. The reversible manner in the local adsorption of microtubules, the flexibility of wire electrodes, and the compatibility between the wire electrode and the bio-molecules are beneficial for spatio-temporal manipulation of the motility machinery in 3 dimensions. [Preview Abstract] |
Wednesday, March 5, 2014 3:54PM - 4:06PM |
Q45.00008: Molecular motor powered nanotransportation guided by carbon nanotubes. A. Sikora, J. Ramon-Azcon, K. Kim, K. Reaves, H. Nakazawa, M. Umetsu, I. Kumagai, T. Adschiri, H. Shiku, T. Matsue, W. Hwang, W. Teizer Due to a decrease in the channel size of nanodevices, pressure-driven transport is increasingly limited by the fluid viscosity. This can be overcome by utilizing the motor protein kinesin that can walk processively along the microtubule filaments for active transport. However, using the kinesin-based transport system requires the ability to control the location and orientation of microtubules. We introduce functionalized multi-wall carbon nanotube (MWNT) tracks, aligned by dielectrophoresis, to guide kinesin powered microtubule shuttles. In order to resist shear flow and the force exerted by an electric field, the MWNT are attached to the surface via a biotin/streptavidin link. The configuration of the aligned MWNT is investigated using scanning electron microscopy and the guiding performance of the MWNT tracks is studied using fluorescence microscopy. [Preview Abstract] |
Wednesday, March 5, 2014 4:06PM - 4:18PM |
Q45.00009: Effect of nanopore diameter on translocation speed of single-stranded DNA Rena Akahori, Takahobu Haga, Toshiyuki Hatano, Itaru Yanagi, Takeshi Ohura, Hirotaka Hamamura, tomio Iwasaki, Takahide Yokoi, Takashi Anazawa The effect of reducing a nanopore's diameter on the translocation speed of single-stranded DNA (ssDNA) was investigated. Various-sized nanopores (minimum 2.3 nm) were fabricated using transmission electron microscopy and atomic-layer deposition. Reducing the diameter was found to increase the drag force generated from the DNA-nanopore interaction and from viscous drag, thereby slowing down the translocation speed. The drag force of ssDNA was weaker than that of double-stranded DNA (dsDNA). These findings were supported by a molecular dynamics (MD) simulation which predicted that reducing nanopore diameter to almost the same as that of ssDNA (i.e., 1.4 nm) would decrease DNA translocation speed (to 1.4 $\mu $s/base) and decrease its variation. Reducing the nanopore diameter is thus a highly effective means of sequencing nanopore DNA. [Preview Abstract] |
Wednesday, March 5, 2014 4:18PM - 4:30PM |
Q45.00010: Vertical electric field stimulation of neural cells on porous amorphous carbon electrodes Shilpee Jain, Ashutosh Sharma, Bikramjit Basu We demonstrate the efficacy of amorphous macroporous carbon substrates as electrodes to stimulate neuronal cell proliferation in presence of external electric field. The electric field was applied perpendicular to carbon electrode, while growing mouse neuroblastoma (N2a) cells \textit{in vitro}. The placement of the second electrode outside of the cell culture medium allows the investigation of cell response to electric field without the concurrent complexities of submerged electrodes such as potentially toxic electrode reactions, electro-kinetic flows and charge transfer (electrical current) in the cell medium. The macroporous carbon electrodes are uniquely characterized by a higher specific charge storage capacity (0.2 mC/cm$^{\mathrm{2}})$ and low impedance (3.3 k$\Omega $ at 1 kHz). When a uniform or a gradient electric field was applied perpendicular to the amorphous carbon substrate, it was found that the N2a cell viability and neurite length were higher at low electric field strengths ($\le $ 2.5 V/cm) compared to that measured without an applied field (0 V/cm). Overall, the results of the present study unambiguously establish the uniform/gradient vertical electric field based culture protocol to stimulate neurite outgrowth and viability of nerve cells. [Preview Abstract] |
Wednesday, March 5, 2014 4:30PM - 4:42PM |
Q45.00011: Systematic decay of Raman signal on DNA Origami-based SERS substrates: analysis of the hot spots Mauricio Pilo-Pais, Anne Watson, Steven Demers, Thom LaBean, Gleb Finkelstein We studied the decay of Raman signal measured on self-assembled DNA origami-based substrates. Specifically, a rectangular origami ($\sim$ 70x90nm$^2$) was used to selectively attach gold nanoparticles ($\sim$ 5 nm) onto its corners, which were subsequently enlarged using a solution-based silver deposition. Further, 4-aminobenzenethiol (ABT) molecules were covalently attached to the assemblies. The assemblies were engineered to form ``hot spots'' of enhanced electromagnetic field between the nanoparticles, resulting in a significant enhancement of Raman signal compared to ABT molecules attached to individual nanoparticles. The signal systematically decayed as a function of the laser exposure time. The one-particle control samples showed no bleaching. We explain this behavior by the bleaching of the molecules due to the high intensity of the electric field at the hot spots. We further increased the laser intensity, allowing us to progressively burn molecules located in the regions within the hot spots where the field intensity exceeded the critical value. The analysis of the signal decay allow us to analyze the field enhancement in the hot spots and quantify the effectiveness of the DNA-origami-based SERS substrates. [Preview Abstract] |
Wednesday, March 5, 2014 4:42PM - 4:54PM |
Q45.00012: Silk/nano-material hybrid: properties and functions Eden Steven, Victor Lebedev, Elena Laukhina, Vladimir Laukhin, Rufina G. Alamo, Concepcio Rovira, Jaume Veciana, James S. Brooks Silk continues to emerge as a material of interest in electronics. In this work, the interaction between silk and conducting nano-materials are investigated. Simple fabrication methods, physical, electronic, thermal, and actuation properties are reported for spider silk / carbon nanotube (CNT-SS) [1] and \textit{Bombyx mori} / (BEDT-TTF)-based organic molecular conductor hybrids (ET-S). The CNT-SS fibers are produced via water and shear assisted method, resulting in fibers that are tough, custom-shapeable, flexible, and electrically conducting. For ET-S bilayer films, a layer transfer technique is developed to deposit linked crystallites of (BEDT-TTF)$_{2}$I$_{3}$ molecular conductor onto silk films, generating highly piezoresistive semi-transparent films. In both cases, the hybridization allows us to gain additional functions by harnessing the water-dependent properties of silk materials, for example, as humidity sensor and electrical current- or water-driven actuators. SEM, TEM, FT-IR, and resistance measurements under varying temperature, strain, and relative humidity reveal the synergistic interactions between the bio- and nano-materials.\\[4pt] [1] E. Steven, et al. Nat. Commun. 4, 2435 (2013). [Preview Abstract] |
Wednesday, March 5, 2014 4:54PM - 5:06PM |
Q45.00013: Cellular Silica Encapsulation for Development of Robust Cell Based Biosensors Robert Johnston, Snezna Rogelj, Jason Harper, Michaelann Tartis In order to detect chemical and biological threats both on the battlefield and in civilian life, development of portable, robust detection systems capable of real-time identification of the chemical and biological agents are needed. Living cell--based sensors have proven effective as sensitive, specific, near real-time detectors; however, living cell-based sensors require frequent cell replenishment due to cell sensitivity to the ex-vivo environment, which limits sensor stability. Incorporation of living cells within a biocompatible matrix that provides mechanical protection and maintains access to the external environment may facilitate the development of long-term stable cell-based biosensors. We are exploring the use of a novel Chemical Vapor into Liquid (CViL) deposition process for whole cell encapsulation in silica. In CViL, the high vapor pressure of common silica alkoxides is utilized to deliver silica into an aqueous medium, creating a silica sol. Mixing of cells with the resulting silica sol facilitates encapsulation of cells in silica while minimizing cell contact with the cytotoxic products of silica generating reactions. Using fluorescence microscopy analysis with multiple silica specific markers, encapsulation of multiple eukaryotic cell types (Saccharomyces cerevisiae, Jurkat, HeLa, and U87 cells) with CViL generated silica is shown, providing a foundation for development of long --term stable cell-based biosensors with diverse sensing capabilities. [Preview Abstract] |
Wednesday, March 5, 2014 5:06PM - 5:18PM |
Q45.00014: Effect of (Ag, Sn) Doping on the Structure and Optical Properties of Au Nanocluster Radhakrishnan Balu, Shashi Karna Noble metal nanoclusters (NCs) consisting of a few to 35 atoms in size in the sub 2 nm range dimension are considered to be nontoxic as opposed to nanoparticles that are cytotoxic. Also, due to the quantum confinement of electrons, these NCs exhibit atom-like energy spectrum and display fluorescent properties useful in a wide range of applications, including medical diagnosis. The unique features of NCs such as size-tunable optical properties, intense fluorescence in the visible, and biocompatibility have stimulated an active area of investigation of noble metal NCs comprised of Au, Ag, Cu, and Pt. Furthermore, the electronic properties of nanoclusters can be modified by combining them with other elements. In this study, we consider the space-filled configuration of Au$_{32}$ NC and investigate the effects of Ag and Sn atom incorporation on geometry and electronic spectrum. Our study suggests that Ag and Sn doping of Au$_{32}$ NC red-shifts the absorption maximum and also reduces the oscillator strength. [Preview Abstract] |
Wednesday, March 5, 2014 5:18PM - 5:30PM |
Q45.00015: A highly sensitive magnetic biosensor for detection and quantification of anticancer drugs tagged to superparamagnetic nanoparticles J. Wingo, J. Devkota, T.T.T. Mai, X.P. Nguyen, P. Mukherjee, H. Srikanth, M.H. Phan A precise detection of low concentrations of biomolecules attached to magnetic nanoparticles in complex biological systems is a challenging task and requires biosensors with improved sensitivity. Here, we present a highly sensitive magnetic biosensor based on the magneto-reactance (MX) effect of a Co$_{65}$Fe$_{4}$Ni$_{2}$Si$_{15}$B$_{14}$ amorphous ribbon with nanohole-patterned surface for detection and quantification of anticancer drugs (Curcumin) tagged to Fe$_{3}$O$_{4}$ nanoparticles. The detection and quantification of Curcumin were assessed by the change in MX of the ribbon subject to varying concentrations of the functionalized Fe$_{3}$O$_{4}$ nanoparticles. A high capacity of the MX-based biosensor in quantitative analysis of the nanoparticles was achieved in the range of 0 - 50 ng/ml, beyond which the detection sensitivity ($\eta )$ remained unchanged. The $\eta $ of the biosensor reached an extremely high value of 30{\%}, which is about 4-5 times higher than that of a magneto-impedance (MI) based biosensor. This biosensor is well suited for detection of low-concentration magnetic biomarkers in biological systems. [Preview Abstract] |
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