Instant nanodots grow on silicon to form sensing array

Dec 02, 2011

Scientists have shown that it is now possible to simultaneously create highly reproductive three-dimensional silicon oxide nanodots on micrometric scale silicon films in only a few seconds. Xavier Landreau and his colleagues at the University of Limoges, France, demonstrated in their paper to be published in EPJD¹ that they were able to create a square array of such nanodots, using regularly spaced nanoindents on the deposition layer, that could ultimately find applications as biosensors for genomics or bio-diagnostics.

They used a process called atmospheric pressure plasma-enhanced chemical vapour deposition. This approach is a much faster alternative to methods such as nanoscale lithography, which only permits the deposition of one nanodot at a time. It also improves upon other silicon oxide growth processes that do not make it possible to precisely order the nanodots into an array. In addition, it can be carried out at atmospheric pressure, which decreases its costs compared to low-pressure deposition processes.

One of the authors' goals was to understand the self-organization mechanisms leading to a preferential deposition of the nanodots in the indents. By varying the indents' interspacing, they made it comparable to the average distance travelled by the particles of the deposited material. Thus, by adapting both the indents' spacing and the silicon substrate temperature, they observed optimum self-ordering inside the indents using atomic force microscopy.

The next step in their research will be to investigate how such nanoarrays could be used as nanosensors. They plan to develop similar square arrays on metallic substrates in order to better control the driving forces that produce the highly ordered self-organisation of nanodots. Further research will be needed to give sensing ability to individual nanodots by associating them with probe molecules designed to recognise target molecules to be detected.

Explore further: Tough foam from tiny sheets

More information: European Physical Journal D (EPJ D). DOI 10.1140/epjd/e2011-20503-7

Related Stories

In Brief: Nanodots to the rescue

May 11, 2011

By applying the magnetic properties of iron nanodots to complex materials, a research team has overcome an obstacle to getting ultra-thin or highly strained films to perform on par with their bulk counterparts.

Nanodots Breakthrough May Lead To 'A Library On One Chip'

Apr 28, 2010

A researcher at North Carolina State University has developed a computer chip that can store an unprecedented amount of data - enough to hold an entire library's worth of information on a single chip. The new chip stems from ...

Recommended for you

Tough foam from tiny sheets

12 hours ago

Tough, ultralight foam of atom-thick sheets can be made to any size and shape through a chemical process invented at Rice University.

Graphene surfaces on photonic racetracks

Jul 28, 2014

In an article published in Optics Express, scientists from The University of Manchester describe how graphene can be wrapped around a silicon wire, or waveguide, and modify the transmission of light through it.

Simulating the invisible

Jul 28, 2014

Panagiotis Grammatikopoulos in the OIST Nanoparticles by Design Unit simulates the interactions of particles that are too small to see, and too complicated to visualize. In order to study the particles' behavior, he uses ...

Building 'invisible' materials with light

Jul 28, 2014

A new method of building materials using light, developed by researchers at the University of Cambridge, could one day enable technologies that are often considered the realm of science fiction, such as invisibility ...

User comments : 0