Bulletin of the American Physical Society
Fall 2010 Meeting of the New England Section of APS
Volume 55, Number 13
Friday–Saturday, October 29–30, 2010; Providence, Rhode Island
Session A1: Plenary Session I |
Hide Abstracts |
Room: Barus and Holley 166 |
Friday, October 29, 2010 1:30PM - 1:35PM |
A1.00001: OPENING REMARKS |
Friday, October 29, 2010 1:35PM - 2:20PM |
A1.00002: DNA Dynamics in Nanoconfinement and Electric Fields Invited Speaker: Controlled stretching of DNA molecules is critical for single molecule genomic and polymer physics studies. To date, most devices have relied on hydrodynamic flows to stretch DNA in an unconfined environment. In contrast, we employ electric field gradients to electrophoretically deform DNA. The purely elongational nature of electric field allows us to use very thin nanofluidic channels and thus explore how nanoconfinement can affect stretching. Here we experimentally study DNA stretching dynamics in a nano-slit cross-slot device. We measure three steady-state quantities at varying strain rates: the average extension, the magnitude of extension fluctuations, and the average orientation of the DNA molecules in the electric field. By comparison with the unconfined case, we show that the presence of the nanoconfinement results in a highly-modified coil-stretch transition of the DNA. We develop a model to demonstrate that these experimental observations are directly related to the fact that the confinement alters the conformational energy landscape of the DNA molecules. [Preview Abstract] |
Friday, October 29, 2010 2:20PM - 3:05PM |
A1.00003: CMOS Nanowire Biosensor Systems Invited Speaker: Nanoscale electronic devices have the potential to achieve exquisite sensitivity as sensors for the direct detection of molecular interactions, thereby decreasing diagnostics costs and enabling previously impossible sensing in disparate field environments. Semiconducting nanowire-field effect transistors (NW-FETs) hold particular promise, though contemporary NW approaches are inadequate for realistic applications. We present here a number of top-down fabricated nanowire approaches that are compatible with complementary metal-oxide-semiconductor (CMOS) technology that has not only achieved unprecedented sensitivity, but simultaneously facilitates system-scale integration of nanosensors. These approaches enable a wide range of label-free biochemical and macromolecule sensing applications, such as specific protein and complementary DNA recognition assays, and specific macromolecule interactions at $<$femtomolar concentrations. An important achievement is the introduction of real-time, unlabeled detection capability which allows for fundamental studies of cellular activation, cell type discrimination through the monitoring of live, stimulus-induced cellular response, and live cell peptide-specific immunoresponse. A critical limitation of nanowire sensors is the Debye screening issue which has to date prevented their use in clinical applications and physiologically relevant solutions. We will present an approach that solves this longstanding problem, and demonstrate the detection at clinically important concentrations of cancer biomarkers from whole blood samples. [Preview Abstract] |
Friday, October 29, 2010 3:05PM - 3:35PM |
A1.00004: BREAK
|
Friday, October 29, 2010 3:35PM - 3:40PM |
A1.00005: Engaging High School Students in Research Invited Speaker: |
Friday, October 29, 2010 3:40PM - 4:25PM |
A1.00006: Analysis of Single Molecules and Particles by Active Control in Nanofluidic Devices Invited Speaker: Nanofluidics involves flow of ions, molecules, and fluids in channels with dimensions approaching molecular length scales. In particular, nanofluidic devices offer the capability of single molecule detection by monitoring change in ionic current through nanopores or nanochannels during translocation (passage) of a molecule through the pore. This current signal can yield information about the size, charge, conformation, and molecular interactions within the pore. However, nanopore sensors can typically perform only a single measurement on a molecule, precluding observation of dynamic events and also limiting the ability of the pore to sensitively distinguish between different molecules. To enhance the discrimination ability of nanopore sensors, we are developing methods for active manipulation of single molecules in nanofluidic devices. As a first step, we have demonstrated multiple measurements on the same DNA molecule by active feedback control: upon detection of a translocation signal the voltage bias was reversed, which allowed for hundreds of measurements on the same molecule. Multiple measurements allowed for statistical averaging of the translocation signal, which increased the ability of the pore to distinguish between DNA molecules of different lengths. This approach may lead to rapid single molecule and single particle assays including DNA fragment sizing and enzymatic digestion assays, analysis of colloidal or polymer suspensions, and sizing of biomolecules. [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