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Dielectrophoretic Manipulation and Real‐Time Electrical Detection of Single‐Nanowire Bridges in Aqueous Saline Solutions
Author(s) -
Marcus Matthew S.,
Shang Lu,
Li Bo,
Streifer Jeremy A.,
Beck Joseph D.,
Perkins Edward,
Eriksson Mark A.,
Hamers Robert J.
Publication year - 2007
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.200700130
Subject(s) - dielectrophoresis , nanowire , bridging (networking) , materials science , electrode , microelectrode , nanoscopic scale , nanotechnology , electrical impedance , aqueous solution , ionic bonding , electrohydrodynamics , optoelectronics , computer science , microfluidics , chemistry , ion , electrical engineering , computer network , organic chemistry , engineering
Dielectrophoretic manipulation of nanoscale materials is typically performed in nonionic, highly insulating solvents. However, biomolecular recognition processes, such as DNA hybridization and protein binding, typically operate in highly conducting, aqueous saline solutions. Here, we report investigations of the manipulation and real‐time detection of individual nanowires bridging microelectrode gaps in saline solutions. Measurements of the electrode impedance versus frequency show a crossover in behavior at a critical frequency that is dependent on the ionic strength. We demonstrate that by operating above this critical frequency, it is possible to use dielectrophoresis to manipulate nanowires across electrode gaps in saline solutions. By using electrical ground planes and nulling schemes to reduce the background currents, we further demonstrate the ability to electrically detect bridging and unbridging events of individual nanowires in saline solutions. The ability to both manipulate and detect bridging events with electrical signals provides a pathway toward automated assembly of nanoscale devices that incorporate biomolecular recognition elements.