REVIEW
An Overview of Structural DNA Nanotechnology
Nadrian C. Seeman
Published online: 12 July 2007
Ó
Humana Press Inc. 2007
Abstract Structural DNA Nanotechnology uses unusual
DNA motifs to build target shapes and arrangements.
These unusual motifs are generated by reciprocal exchange
of DNA backbones, leading to branched systems with
many strands and multiple helical domains. The motifs
may be combined by sticky ended cohesion, involving
hydrogen bonding or covalent interactions. Other forms of
cohesion involve edge-sharing or paranemic interactions of
double helices. A large number of individual species have
been developed by this approach, including polyhedral
catenanes, a variety of single-stranded knots, and Borro-
mean rings. In addition to these static species, DNA-based
nanomechanical devices have been produced that are ulti-
mately targeted to lead to nanorobotics. Many of the key
goals of structural DNA nanotechnology entail the use of
periodic arrays. A variety of 2D DNA arrays have been
produced with tunable features, such as patterns and cav-
ities. DNA molecules have be used successfully in DNA-
based computation as molecular representations of Wang
tiles, whose self-assembly can be programmed to perform a
calculation. About 4 years ago, on the fiftieth anniversary
of the double helix, the area appeared to be at the cusp of a
truly exciting explosion of applications; this was a correct
assessment, and much progress has been made in the
intervening period.
Keywords Branched DNA Á Sticky-ended cohesion Á
DNA-based computation Á DNA polyhedra Á DNA
nanomechanical devices Á DNA architecture Á DNA
crystals Á Translation devices Á Nanoparticle organization
Introduction
This is an update of an article written in 2003 [1], the
fiftieth anniversary of the Watson-Crick [2] model for
double helical DNA. The impact of this model during the
past half-century has been immense. Indeed, the double
helix has become a cultural icon of our civilization in much
the same way that the Pyramids of Egypt, the temples of
Greece, the Cathedrals of medieval Europe and the Great
wall of China were icons of previous eras. The simplicity
and elegance of the molecule nature evolved to perpetuate
and express genetic information has revolutionized genet-
ics, and has had a similar impact in other areas ranging
from medicine to forensics. All of these applications are
predicated on the complementarity of the two strands of
DNA, rooted in the hydrogen bonded base pairing between
adenine (A) and thymine (T) and between guanine (G) and
cytosine (C). The DNA double helix is inherently a nano-
scale object; its diameter is about 20 A
˚
(2 nm) and the
separation of the bases is 3.4 A
˚
; the helical periodicity is
10–10.5 nucleotide pairs per turn, or ~3.5 nm per turn.
Here, we will discuss making complex materials with
nanoscale features from DNA; this pursuit is termed
structural DNA nanotechnology. This area began in the
early 1980s [3], and had made significant progress by 2003;
the intervening period has seen remarkable progress, which
will be summarized here, along with the basic principles,
which are largely the same.
What purposes would be served by producing DNA-
based constructs? We expect these systems can be applied
to several practical ends: The initial motivating goal for
this research is that spatially periodic networks are crystals.
If we can build stick-figure crystalline cages on the nano-
meter scale, they could be used to orient other biological
macromolecules as guests inside those cages, thereby
N. C. Seeman (&)
Department of Chemistry, New York University, New York, NY
10003, USA
e-mail: ned.seeman@nyu.edu
Mol Biotechnol (2007) 37:246–257
DOI 10.1007/s12033-007-0059-4