BIOTECHNOLOGY 17
Nanofabrication technology could lead to detection breakthrough
Scientists in the US have made a breakthrough with a DNA-based nanofabrication technology that could revolutionise how sensing and detection technologies operate. Sean Ottewell explains.
Aux États-Unis, des scientifiques ont effectué une percée avec une technologie de nanofabrication à base d’ADN qui pourrait bien révolutionner la façon dont fonctionnent les technologies d’exploration et de détection. Les explications de Sean Ottewell.
Wissenschaftler in den USA haben einen Durchbruch bei den Nanofertigungsverfahren auf DNA-Basis erreicht, der die Funktionsweise von Erkennungs- und Nachweisverfahren grundlegend verändern könnte. Ein Bericht von Sean Ottewell.
have designed a molecular assembly line for predictable, high-precision nano-construction. Such reliable, reproducible nanofabrication is
B
essential for exploiting the unique properties of nanoparticles in applications such as biological sensors. The work was published online in the 29 March issue of Nature Materials. The Brookhaven team has previously used DNA to link up nanoparticles in various arrangements, including 3D nano-crystals. The idea is that nanoparticles coated with complementary strands of DNA - segments of genetic code sequence that bind only with one another like highly specific Velcro - help the nanoparticles find and stick to one another in highly specific ways. By varying the use of complementary DNA
and strands that do not match, scientists can exert precision control over the attractive and repulsive forces between the nanoparticles to achieve the desired construction. Note that the short DNA linker strands used in these studies were constructed artificially in the laboratory and do not code for any proteins, as genes do. The latest advance
has been to use the DNA linkers to attach some of the DNA-coated nanoparticles to a solid surface to further constrain and control how the nanoparticles can link up. This yields even greater precision, and therefore a more predictable, reproducible high- throughput construction technique for building clusters from nanoparticles. “When a particle is
attached to a support surface, it cannot react with other molecules or particles in the same way
Fig. 1. This transmission electron micrograph shows nanoparticle dimers (two-particle clusters) assembled and released through the DNA-encoded solid-support approach.
www.scientistlive.com
uilding on the idea of using DNA to link up nanoparticles scientists at the US Department of Energy’s (DOE) Brookhaven National Laboratory
as a free-floating particle,” explained Brookhaven physicist Oleg Gang, who led the research at the Lab’s Centre for Functional Nanomaterials. This is because the support surface blocks about half of the particle’s reactive surface. Attaching a DNA linker or other particle that specifically interacts with the bound particle then allows for the rational assembly of desired particle clusters. “By controlling the number of DNA linkers and their length, we can regulate interparticle distances and a cluster’s architecture,” said Gang. “Together with the high specificity of DNA interactions, this surface-anchored technique permits precise assembly of nano-objects into more complex structures.” Instead of assembling millions and millions
of nanoparticles into 3D nanocrystals, as was done in the previous work, this technique allows the assembly of much smaller structures from individual particles. In the paper, the scientists describe the details for producing symmetrical, two-particle linkages, known as dimers (Fig. 1), as well as small, asymmetrical clusters of
➠
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44