Analytica 2008 looks to future of nano-analysis

The prefix 'nano' comes from the Greek word 'nanos' (dwarf), so as terminology goes, it is an understatement: A nanometer is actually one billionth of a metre.

Nanotechnology, on the other hand, is a technique used to produce or manipulate structures of that size.

If one were to enlarge a small child to the same order of magnitude, ie, a billion times, then it could reach the moon with outstretched arms and hold it between its fingers like a tiny pearl.

According to international analysts, nanotechnology accounts for global market volume in the double-digit billion dollar range.

Like other sectors, analysis profits from this boom considerably: on the one hand, nanotechnology has several potential new applications and thus growth opportunities in the analysis sector.

The industry is on the verge of a quantum leap in development because many options are still on the horizon or considered visions at their current stage.

On the other hand, analysis methods are needed that will allow the industry to penetrate the various dimensions of nanotechnology in a comprehensive and meaningful manner.

New developments are imminent in this case, as well.

Nano-analysis: a new interdisciplinary technology.

Consequently, the development of new or optimised analysis techniques in the nano-range plays an extremely important role when it comes to progress in the future discipline of nanotechnology as a whole.

The reason is obvious: producing nano-scale structures would simply be unthinkable without appropriate analysis techniques.

The techniques and equipment used in nano-analysis serve as a sort of eye for viewing nanostructures and as a finger for touching the structures and making specific alternations.

At the same time, nano-analysis is also an interdisciplinary technology that is used to perform important service functions in other technological sectors.

While nano-analysis of inorganic samples such as semiconductors is already established, ongoing development is still needed to analyze biological systems.

Nano opening up new markets for analysis.

According to a study by Agit (Aachen Society for Innovation and Technology Transfer) and the Aachen Competence Center for Medical Technology, the convergence of nanotechnology and analysis is giving rise to entirely new markets.

Examples include diagnostics and medical technology - among other things, when it comes to new contrast agents or medicating patients, minute quantities of active ingredients can be admitted using coated nano-particles.

The latest transmission-electron microscopes (TEM) are needed to take analysis measurements in the nanometer range.

When it comes to heavy atoms with high electron densities, these devices provide good contrasts and good images if so-called HAADF scanning methods are use (HAADF stands for high-angle annular dark field).

This is helpful when analysing nanoparticle systems such as catalysts.

Catalysts frequently consist of nano-scale metal particles that are applied to oxidized substrates.

In many cases, two metals are used, ie, one to control the activity, the other to control selectivity.

To ensure that the catalyst is both active and selective, both metals must be present in the nanometer-sized metal particle, and in a predefined quantity.

If they are, it can be verified using the ring-shaped HAADF scanning method in the TEM.

When using this technique, an electron beam just 0.5 to 1nanometer wide raster-scans the sample and measures the electrons that are scattered at a wide angle behind it using a ring-shaped detector.

The advantages of modern nana-analysis are also noticeable when analysing nano-structured bulk materials.

The properties of polymer fibres depend to a great extent on their structure.

However, when it comes to these materials in particular, it is difficult to get information about their actual state because their structure can change considerably during processing, such as in the extruder.

But now, wide-angle X-ray scattering (Waxs) makes it possible to analyse these fibres without destroying them just as they come out of the extruder.

The principle behind this technique is based on a correlation between the scattering of X-rays and materials that have a more or less long-range order.

Nano-antennae revolutionising diagnostics.

The latest work on the plasmonic effects of nanoparticles is nothing short of spectacular.

Plasmons are electromagnetic waves that spread out along metallic surfaces and bond with the joint surface between a thin metal and a polymer coating.

Appropriate nanostructures make it possible to conduct and process optical signals.

At the Institute for Photonic Technologies at Friedrich Schiller University in Jena, Germany, a team of scientists has found a way to use nano-particles from gold as markings for bioanalysis.

These particles permit optical detection which, technically, is much easier than fluorescence techniques and significantly improves sensitivity during gravimetric detection.

Other promising research and development activities deal with nano-antennas and compact nano-lasers.

Nano-antennas can be used to considerably improve the accuracy of image-producing techniques in medical diagnostics and of instruments used to identify chemical and biological agents.

Nano-antennas use the absorption induced during plasmon resonance to inject energy into the particle using laser pulses.

The procedure itself is particularly gentle and does not damage the surrounding area.

Because of the effect of the nano-antenna, once it is in the vicinity, resolution is determined by the size of the particle and can thus be considerably lower than the wavelength of the light being used.