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Ancient microscopic organisms could become the tools of the future when it comes to advancing material science in areas such as solar cell technology.

Furthermore, a 2008 Honours student has published his proof of the concept in the renowned Journal of the American Chemical Society (JACS).

Jeremiah Toster, who was in the first cohort of Bachelor of Science students to study nanotechnology, has successfully manipulated the silica shells of diatoms so they can be used as platforms for developing useful materials in areas of health, energy and the environment.

He is embarking on his PhD in the Centre for Strategic Nano-fabrication (School of Biomedical, Biomolecular and Chemical Science) working on using diatom shells as a scaffold for solar cells.

Jeremiah and his supervisors, Professor Colin Raston and Dr Iyer Swaminathan, co-authored the article that encapsulated his Honours research.

Scientists around the world are exploring the use of materials reduced to the nanoscale, where they can show very different properties from those they exhibit at a normal scale.

But fabrication at the nanoscale (when a metre is equal to a billion nanometres) is difficult. As a result, the nanotechnology community is turning to the science of biomimicry and emulating nature to solve complex problems.

One such example is the use of diatoms, the single cell microscopic organisms found in both fresh and salt water ecosystems, and believed to be responsible for 25 per cent of the total oxygen produced on Earth. They are the most abundant life form on the planet and their silica shells are readily available from geological deposits. They are perforated with pores measuring between 50 and 200 nanometres.

“These shells are abundant, so why try to make them at the nano-dimension, when nature has provided this perfect structure?” Professor Raston said.

“This material has been precisely engineered by nature, but we needed to be able to manipulate it,” Jeremiah said.

So he developed a method for the assembly of gold nanoparticles around the pores of diatom shells. “We tried other metals but gold was the one that worked,” he said.

“It is brilliant work from an Honours students and remarkable that his proof of concept has been published in such a premium journal,” Professor Raston said.

Jeremiah’s paper was also highlighted in the August edition of the Royal Australian Chemical Institute’s journal, Chemistry in Australia.

“They only publish the best of the best and will only highlight a paper if it’s been published in JACS or a similar, high-impact journal,” Prof. Raston said.

Jeremiah found that he could effectively create three-dimensional arrays of gold nanoparticles using the diatom scaffold, which opens the door to developments in drug delivery and optical applications as well as solar cell technology.

Photos:
Top photo: Jeremiah Toster can tell what size nanoparticles of gold are in this solution since the colour changes with different sizes

An untouched diatom (above) and one with gilded pores (below)

Article courtesy of UWA News.