Electro-Fluidics for Single-Molecule Biophysics

Brown University, Providence RI

Investigators

Abstract

ID: MPS/DMR/BMAT(7623) 0805176 PI: Stein, Derek ORG: Brown University Title: Electro-Fluidics for Single Molecule Biophysics INTELLECTUAL MERIT: This research program will explore the interface between hard and soft matter where charged biomolecules are confined to ultra-small, electrostatically actuated, aqueous environments. Success in this effort will add an important new dimension to ?lab-on-a-chip? devices that have the potential to revolutionize medical diagnostics. Nanofluidic structures will directly apply controllable electrostatic forces to a single, charged biomolecule as follows. A negatively charged DNA molecule that is confined to a nanofluidic channel whose width is comparable to the Debye length will be subjected to forces generated by surface potential gradients. By locally tuning the surface potential using gate electrodes, a potential energy landscape will be created that traps DNA at a local minimum. Individual molecules will thereby be confined and manipulated within purely electrostatic walls. The distinct scientific facets of this objective will be addressed through fundamental studies of: (1) the modulation of the electrostatic forces in ionic solution by gated materials, and (2) the conformational and dynamical response of individual DNA polymers to applied electrostatic forces in well-defined, nanofluidic structures. The resulting insight will guide the development of the envisioned ?electro-fluidic? technology. An electrostatically-actuated gate for the manipulation of a single molecule will be demonstrated. The long-term vision of this work includes the integration of electrostatic gates for testing single-molecule dynamics, and to realize ultra-small bioreactors capable of localizing a single enzymatic reaction, such as DNA transcription. The use of gates to selectively control the contents of a silicon-based, artificial cell should also enable experiments in ?bottom-up? biology, in which the biochemical functionality of the cell can be incrementally enhanced. BROADER IMPACTS: The technology under development in this project not only provides a route to new information about the role of electrostatics in governing the behavior of single polyelectrolyte molecules, it has the potential to provide new control mechanisms for nano-fluidic devices. The project also provides an excellent platform for training of graduate and undergraduate students across the domains of physics, chemistry, biology, and materials science. The PI regularly includes undergraduate students in his research team and is a participant in campus-wide programs that aim to increase the diversity of the scientific workforce. In particular, he is engaged with the Leadership Alliance Program, which seeks to increase participation of underrepresented groups in graduate level programs at leading research institutions, and with the Women in Science and Engineering (WiSE) program, which has served as a channel for attracting female students to join his research group.