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

Published

December 10, 2013

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

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

Pub Type

Journals

Download Paper

https://doi.org/10.1021/la403946j

Local Download

Keywords

nanomotor, acoustofluidics, nanowire

Citation

Ahmed, S. , Wang, W. , Mair, L. , Fraleigh, R. , Li, S. , Castro, L. , Hoyos, M. , Huang, T. and Mallouk, T. (2013), Steering Acoustically Propelled Nanowire Motors towards Cells in a Biologically Compatible Environment using Magnetic Fields, Langmuir, [online], https://doi.org/10.1021/la403946j, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914385 (Accessed October 9, 2025)