2 research outputs found
Self-Propelling Nanomotors in the Presence of Strong Brownian Forces
Motility in living systems is due
to an array of complex molecular
nanomotors that are essential for the function and survival of cells.
These protein nanomotors operate not only despite of but also because
of stochastic forces. Artificial means of realizing motility rely
on local concentration or temperature gradients that are established
across a particle, resulting in slip velocities at the particle surface
and thus motion of the particle relative to the fluid. However, it
remains unclear if these artificial motors can function at the smallest
of scales, where Brownian motion dominates and no actively propelled
living organisms can be found. Recently, the first reports have appeared
suggesting that the swimming mechanisms of artificial structures may
also apply to enzymes that are catalytically active. Here we report
a scheme to realize artificial Janus nanoparticles (JNPs) with an
overall size that is comparable to that of some enzymes ā¼30
nm. Our JNPs can catalyze the decomposition of hydrogen peroxide to
water and oxygen and thus actively move by self-electrophoresis. Geometric
anisotropy of the PtāAu Janus nanoparticles permits the simultaneous
observation of their translational and rotational motion by dynamic
light scattering. While their dynamics is strongly influenced by Brownian
rotation, the artificial Janus nanomotors show bursts of linear ballistic
motion resulting in enhanced diffusion
Self-Propelling Nanomotors in the Presence of Strong Brownian Forces
Motility in living systems is due
to an array of complex molecular
nanomotors that are essential for the function and survival of cells.
These protein nanomotors operate not only despite of but also because
of stochastic forces. Artificial means of realizing motility rely
on local concentration or temperature gradients that are established
across a particle, resulting in slip velocities at the particle surface
and thus motion of the particle relative to the fluid. However, it
remains unclear if these artificial motors can function at the smallest
of scales, where Brownian motion dominates and no actively propelled
living organisms can be found. Recently, the first reports have appeared
suggesting that the swimming mechanisms of artificial structures may
also apply to enzymes that are catalytically active. Here we report
a scheme to realize artificial Janus nanoparticles (JNPs) with an
overall size that is comparable to that of some enzymes ā¼30
nm. Our JNPs can catalyze the decomposition of hydrogen peroxide to
water and oxygen and thus actively move by self-electrophoresis. Geometric
anisotropy of the PtāAu Janus nanoparticles permits the simultaneous
observation of their translational and rotational motion by dynamic
light scattering. While their dynamics is strongly influenced by Brownian
rotation, the artificial Janus nanomotors show bursts of linear ballistic
motion resulting in enhanced diffusion