Tuesday, April 15, 2014
Chemical Physics Seminar
Macromolecular Translocation Through Nanopores
Murugappan Muthukumar, Wilmer D. Barrett Professor of Polymer Science and Engineering, Department of Polymer Science and Engineering, University of Massachusetts, Amherst
The ubiquitous phenomenon of translocation of electrically charged macromolecules through narrow pores exhibits bewildering phenomenology, requiring an adequate description of polyelectrolyte dynamics, electrolyte dynamics, hydrodynamics, and confinement effects from charge-decorated pores. The translocation process involves three major stages: (a) approach of the macromolecule towards the pore, (b) capture/recognition of the macromolecule at the pore entrance, and (c) threading through the pore. All of these stages are controlled by conformational entropy of the macromolecule, charge decoration and the geometry of the pore, hydrodynamics, and electrostatic interactions. Challenges in developing a unified theory of these contributing factors will be described in the context of a few illustrative experimental data on transport of DNA, proteins, and synthetic macromolecules through protein pores and solid-state nanopores.