Corral Trapping of Single Molecules in Solution: Theory and Applications

Abstract

One of the great outstanding challenges for the fabrication of nanosensors and nanodevices that will drive future technologies and enable the planned assembly of molecular-scale devices is the controlled manipulation of nanoscale objects, and particularly of single molecules. Any such manipulation is preceded by an efficient, reliable method for confining (trapping) an object on demand, which has remained a formidable task in the case of single molecules.We have successfully trapped single molecule ions and other charged particles in aqueous electrolytes using a purely electrostatic setup, demonstrating stable and reversible confinement of single and multiple particles to nanoscale dimensions over extended periods of time.Here, we will present some of the experimental results and discuss potential mechanisms for corral trapping. Electrokinetic phenomena such as electrohydrodynamic flow, electroosmotic flow, or dielectrophoresis are known to occur near a charged metal electrode; however, we attribute corral trapping to direct charge-field interactions, i.e. and electrostatic or electrophoretic mechanism, which seems consistent with all experimental observations. Theoretical modeling of the entire setup using the finite element method will be discussed, and the limitations for applications in SNP detection and water treatment technologies will be explored.View Large Image | View Hi-Res Image | Download PowerPoint Slide