NIST logo

Publication Citation: Steering Acoustically Propelled Nanowire Motors towards Cells in a Biologically Compatible Environment using Magnetic Fields

NIST Authors in Bold

Author(s): Suzanne Ahmed; Wei Wang; Lamar O. Mair; Robert D. Fraleigh; Sixing Li; Luz A. Castro; Mauricio Hoyos; Tony J. Huang; Thomas E. Mallouk;
Title: Steering Acoustically Propelled Nanowire Motors towards Cells in a Biologically Compatible Environment using Magnetic Fields
Published: December 10, 2013
Abstract: The recent discovery of fuel-free propulsion of nanomotors using acoustic energy has provided a new avenue for using nanomotors in biocompatible media. Crucial to the application of nanomotors in biosensing and biomedical applications is the ability to remotely control and steer them towards targets of interest such as specific cells and tissues. We demonstrate in vitro magnetic steering of acoustically powered nanorod motors in a biologically compatible environment. Steering was accomplished by incorporating (40 ± 5) nm thick nickel stripes into the electrochemically grown nanowires. An external magnetic field of 15 mT to 40 mT was used to orient the motors, which were acoustically propelled along their long axes. In the absence of a magnetic field, (300 ± 30) nm diameter, (4.3 ± 0.2) µm long nanowires with (40 ± 5) nm thick magnetic stripes exhibit the same self-acoustophoretic behavior, including pattern formation into concentric nanowire circles, aligned spinning chains and autonomous axial motion, as their non-magnetic counterparts. In a magnetic field these wires and their paths are oriented as evidenced by their comparatively linear trajectories. Coordinated motion of multiple motors and targeting of individual motors towards HeLa cells with micron-level precision was demonstrated.
Citation: Langmuir
Volume: 29
Issue: 52
Pages: pp. 16113 - 16118
Keywords: nanomotor; acoustofluidics; nanowire
Research Areas: Nanowires, Nanostructured Materials, Nanobiotechnology, Nanomaterials
DOI: http://dx.doi.org/http://pubs.acs.org/doi/abs/10.1021/la403946j  (Note: May link to a non-U.S. Government webpage)
PDF version: PDF Document Click here to retrieve PDF version of paper (11MB)