posted on 2016-10-09, 00:00authored byXing Ma, Ana C. Hortelao, Albert Miguel-López, Samuel Sánchez
The motion of self-propelled
tubular micro- and nanojets
has so far been achieved by bubble propulsion, e.g., O2 bubbles formed by catalytic decomposition of H2O2, which renders future biomedical applications inviable.
An alternative self-propulsion mechanism for tubular engines on the
nanometer scale is still missing. Here, we report the fabrication
and characterization of bubble-free propelled tubular nanojets
(as small as 220 nm diameter), powered by an enzyme-triggered biocatalytic
reaction using urea as fuel. We studied the translational and rotational
dynamics of the nanojets as functions of the length and location
of the enzymes. Introducing tracer nanoparticles into the system,
we demonstrated the presence of an internal flow that extends into
the external fluid via the cavity opening, leading to the self-propulsion.
One-dimensional nanosize, longitudinal self-propulsion, and
biocompatibility make the tubular nanojets promising for
future biomedical applications.