This is Ned Seeman again,
and now we're going to go on
to the second part of this talk.
And here we're going to discuss
organizing other materials with DNA,
not just DNA by itself.
And we're also gonna talk about
of structural DNA nanotechnology,
namely machines that change
their states, and walkers,
and the combination of these things
even to make a nanoscale assembly line
within the structure.
On the next slide, we're gonna show
how we can organize
other chemical species.
So the first thing
that I'll talk about is organizing
5nm and 100nm gold nanoparticles
in two dimensions,
work done by Jiwen Zheng
and Pam Constantinou from my lab,
and Paul Alivisatos from Berkeley,
and Rick Kiehl when he was at Minnesota.
So we can see that we have
a tensegrity triangle where,
now it's bigger than it was before,
each of the edges is the DX molecule,
rather than just a single duplex.
And these guys
are about eight turns long.
And we can make
a two-dimensional array
just by using two of the sticky ends
either with one tile or two tiles,
just like we did in three-dimensions.
Here we can see how we're going
to attach a nanoparticle.
So we're going to propagate
in the horizontal direction
and we're going to propagate
in the lower left,
upper right direction.
But in the third direction,
we're going to cover up
the sticky end on one side
with a nanoparticle
to which there is only
one piece of DNA attached,
that's the Alivisatos chemistry.
And it's attached, in this case,
to this red strand,
which is an inherent component
of the entire tensegrity triangle motif.
So it binds in there
and it takes with it a nanoparticle.