Printing With Enzymes

Roland Piquepaille writes "Researchers at Duke University have developed a new printing technique using catalysts to create microdevices such as labs-on-a-chip. Their inkless printing technique uses enzymes from E. coli bacteria and has an accuracy of less than 2 nanometers. While they're are now using enzymes to stamp nanopatterns without ink, the research team is already working with non-enzymatic catalysts. And it added that 'future versions of the inkless technique could be used to build complex nanoscale devices with unprecedented precision.'"

Least accuracy?

[melonman]

Shouldn't that be "resolution of less than 2 nanometers", or maybe "accuracy better than 2 nanometers"?

Re:Osama Bin Lexmark

[wizardforce]

all Ecoli are not the same, some strains are bad, some are good. The process has virtually no chance of causing any dangerous effects that were not already there from Ecoli strains in the wild. If it really concerns you that Ecoli of any strain got out, a number of safegaurds can and likely will be used. for example, a set of genes for key metabolic processes can be removed making the bacteria completely dependent on the special environment in the printers/labs etc.

To put it a different way, what if colonies of harmless bacteria (called biofilms) that often dwell in water systems, like the bacteria that harmlessly inhabit the human gut, were to trap pathogens and shield them from disinfectants?

biofilms are not simply harmless bacteria, biofilms are generally a large colony of bacteria working together to form what amounts to a bacteria-made protective environment. they can infact be the cause of serious disease because they are more resistant to changing environmental conditions than free living bacteria. the biofilms can be composed of harmful bacteria although harmful bacteria generally are capable of making their own biofilms without the assistance of "good bacteria"

Dot's all!

[kanweg]

They can create a dot (circular area) with a diameter of 2 nm. That is the area an enzyme dangling from a linker (tether) can reach. It is not that they can create anything other than a dot, not that they can put purposively 2 dots at a distance of 2 nm from each other, or that they can add material (such as a metal capable of functioning as a conductor) on the surface. Really nice experiment, but don't buy shares unless you're a long-term investor.

Bert

the actual reference...

[kebes]

Yet another scientific story with big claims and little detail. 2nM accuracy sounds a little overstated.

Indeed. The news release misses the point of the paper somewhat.

The actual scientific paper appears to be this one:
Phillip W. Snyder, Matthew S. Johannes, Briana N. Vogen, Robert L. Clark, and Eric J. Toone, "Biocatalytic Microcontact Printing [acs.org]" J. Org. Chem., 72 (19), 7459 -7461, 2007 DOI: 10.1021/jo0711541 [doi.org]

Second they are using fluorescence to see the pattern and this at the very best has resolution of about 300nM.

They use confocal fluorescence which is, as you note, diffraction limited. However for the high-resolution study of the line-edges, they use Atomic Force Microscopy [wikipedia.org] which is of course much higher resolution. The AFM images they show, however, appear to have rather imperfect line-edges, with resolution of >200 nm. Actually, nowhere in the paper do they claim to have demonstrated 2 nm resolution. Rather, they point out in the introduction that their new technique, in principle, could allow higher-resolution printing that conventional soft lithography, because there is no diffusion of reagents in their technique. The news release focuses on this mention of a theoretical 2 nm resolution, rather than pointing out the actual accomplishment of the paper, which in the words of the authors is:

In conclusion, we have demonstrated the feasibility of biocatalytic lithography. Catalyst-mediated soft lithographic technique offers the advantage of lateral resolution controlled by the range of motion of the immobilized catalyst rather than by the diffusive properties of molecular inks. This feature should facilitate the implementation of strategies for stamping nanoscale features. Further examination of stamping parameters and the application of this methodology to nanolithography are underway, and we will report our results in due course.

So, in short, it's an important advancement but the authors are not claiming to have achieved the intended ultra-high-resolution yet. And, even without that optimistic resolution, the technique is interesting in its own right because it is a new way to control the nanoscale chemical patterning of surfaces.

Re:To the Roland haters.

[h4rm0ny]

I guess it's just because he keeps summerising articles, adding nothing, introducing errors or misunderstandings, all for the purpose of interposing his ads and site-stat boosting in between us and the original article. ohnoitsroland is my favourite tag ever and I consider it a service to us all if someone can get a link to the original article in quickly near the top of the comments.