Faculty of Science and Technology

MWCNTs (red) at the surface of a wheat root (Green)

Engineered nanomaterials occupy a transitional position between the atomic and microscale where they have novel physico-chemical properties which can be tuned with size shape and structure. These properties can be very different from the bulk state, offering versatility within a wide range of applications, from textiles, paints and personal car products, to targeted drug delivery, land remediation or specialised lasers. Engineered nanomaterials have huge potential application but also unknown environmental fate and behaviour.

To understand the environmental fate and behaviour of nanoparticles, we need to understand how they behave in typical environmental conditions and what properties of the nanomaterials govern their behaviour.

One of the fundamental gaps identified is the need to develop methods that can detect nanomaterials in living systems at the cellular scale, for instance bacterial or fungal communities and plants.

At Lancaster Dr Edward Wild has been developing novel bio-imaging techniques for environmental chemistry, to detect and visualise the real time cellular uptake fate and behaviour of environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) by plant and microbial communities. This has been achieved through the combination of two-photon excitation microscopy and autofluorescence.

We have now developed this technique for the in-vivo detection and visualisation of a range of nanomaterials of environmental concern, including titanium dioxide (TiO2) and cerium dioxide (CeO2) nanoparticles and multiwalled carbon nanotubes (MWCNTs), which we have visualised simultaneously with wheat roots and a range of PAHs.

The imaging of nanomaterials alongside individual cells or whole tissue structures over scales of hundreds of nanometres to hundreds of micrometers can be achieved. Nanomaterials which have been taken up into cells can be monitored alongside chemicals which have sorbed to the nanomaterials. The non-destructive nature of TPEM means that samples can be visualised and monitored in real time over extended time periods.

A new article in Environmental Science and Technology outlines the potential of this technique for the in-vivo visualisation of certain nanomaterials and their interactions with organic chemicals and highlight its potential uses with both in-vivo and in vitro systems to identify cellular uptake, storage, or degradation, and look at future applications with bacteria, fungi, lung tissues and skin.

Wed 10 June 2009

Associated Links

• Environmental Science and Technology - Article outlining in-vivo visualisation potential.
• Nanotubes boost plant pollutants - Article on the Royal Society of Chemistry website.