title: Gold Nanorod Rotary Motors Driven by Resonant Light Scattering.
abstract: Efficient and robust artificial nanomotors could provide a variety of exciting possibilities for applications in physics, biology and chemistry, including nanoelectromechanical systems, biochemical sensing, and drug delivery. However, the application of current man-made nanomotors is limited by their sophisticated fabrication techniques, low mechanical output power and severe environmental requirements, making their performance far below that of natural biomotors. Here we show that single-crystal gold nanorods can be rotated extremely fast in aqueous solutions through optical torques dominated by plasmonic resonant scattering of circularly polarized laser light with power as low as a few mW. The nanorods are trapped in 2D against a glass surface, and their rotational dynamics is highly dependent on their surface plasmon resonance properties. They can be kept continuously rotating for hours with limited photothermal side effects and they can be applied for detection of molecular binding with high sensitivity. Because of their biocompatibility, mechanical and thermal stability, and record rotation speeds reaching up to 42 kHz (2.5 million revolutions per minute), these rotary nanomotors could advance technologies to meet a wide range of future nanomechanical and biomedical needs in fields such as nanorobotics, nanosurgery, DNA manipulation and nano/microfluidic flow control.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology , S-412 96 Göteborg, Sweden.
authors.forename: Lei
authors.initials: L
authors.lastname: Shao
authors.affiliation: Department of Applied Physics, Chalmers University of Technology , S-412 96 Göteborg, Sweden.
authors.forename: Zhong-Jian
authors.initials: ZJ
authors.lastname: Yang
authors.affiliation: Department of Applied Physics, Chalmers University of Technology , S-412 96 Göteborg, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Andrén
authors.affiliation: Department of Applied Physics, Chalmers University of Technology , S-412 96 Göteborg, Sweden.|School of Science and Technology, Örebro University , S-701 82 Örebro, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Johansson
authors.affiliation: Department of Applied Physics, Chalmers University of Technology , S-412 96 Göteborg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Käll
mesh_terms: D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D008027:Light; D036103:Nanotechnology; D043942:Nanotubes / Q000737:chemistry*; D052898:Optical Tweezers; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods
chemical_list: D006046:Gold
keywords: gold nanorods; light scattering; nanomotors; optical tweezers; surface plasmon