Tag Archives: Heike Ebendorff-Heidepriem

Luminescent upconversion nanoparticles could make imaging more efficient

Researchers at the University of Adelaide (Australia) have found a way to embed luminiscent nanoparticles in glass, according to a June 8, 2016 news item on Nanotechnology,

This new “hybrid glass” successfully combines the properties of these special luminescent (or light-emitting) nanoparticles with the well-known aspects of glass, such as transparency and the ability to be processed into various shapes including very fine optical fibres.

The research, in collaboration with Macquarie University and University of Melbourne, has been published online in the journal Advanced Optical Materials.

A June 7, 2016 University of Adelaide press release (also on EurekAlert), which originated the news item, offers more detail,

“These novel luminescent nanoparticles, called upconversion nanoparticles, have become promising candidates for a whole variety of ultra-high tech applications such as biological sensing, biomedical imaging and 3D volumetric displays,” says lead author Dr Tim Zhao, from the University of Adelaide’s School of Physical Sciences and Institute for Photonics and Advanced Sensing (IPAS).

“Integrating these nanoparticles into glass, which is usually inert, opens up exciting possibilities for new hybrid materials and devices that can take advantage of the properties of nanoparticles in ways we haven’t been able to do before. For example, neuroscientists currently use dye injected into the brain and lasers to be able to guide a glass pipette to the site they are interested in. If fluorescent nanoparticles were embedded in the glass pipettes, the unique luminescence of the hybrid glass could act like a torch to guide the pipette directly to the individual neurons of interest.”

Although this method was developed with upconversion nanoparticles, the researchers believe their new ‘direct-doping’ approach can be generalised to other nanoparticles with interesting photonic, electronic and magnetic properties. There will be many applications – depending on the properties of the nanoparticle.

“If we infuse glass with a nanoparticle that is sensitive to radiation and then draw that hybrid glass into a fibre, we could have a remote sensor suitable for nuclear facilities,” says Dr Zhao.

To date, the method used to integrate upconversion nanoparticles into glass has relied on the in-situ growth of the nanoparticles within the glass.

“We’ve seen remarkable progress in this area but the control over the nanoparticles and the glass compositions has been limited, restricting the development of many proposed applications,” says project leader Professor Heike Ebendorff-Heideprem, Deputy Director of IPAS.

“With our new direct doping method, which involves synthesizing the nanoparticles and glass separately and then combining them using the right conditions, we’ve been able to keep the nanoparticles intact and well dispersed throughout the glass. The nanoparticles remain functional and the glass transparency is still very close to its original quality. We are heading towards a whole new world of hybrid glass and devices for light-based technologies.”

Here’s a link to and a citation for the paper,

Upconversion Nanocrystal-Doped Glass: A New Paradigm for Photonic Materials by Jiangbo Zhao, Xianlin Zheng, Erik P. Schartner, Paul Ionescu, Run Zhang, Tich-Lam Nguyen, Dayong Jin, and Heike Ebendorff-Heidepriem. Advanced Optical Materials DOI: 10.1002/adom.201600296 Version of Record online: 30 MAY 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Gold detection down to the nanoparticle?

It appears that detecting gold, presumably for mining purposes, isn’t as easy as one might think especially at the nanoscale. Researchers at Australia’s University of Adelaide have devised a new method according to an April 29, 2015 news item on Nanowerk (Note: A link has been removed),

University of Adelaide researchers are developing a portable, highly sensitive method for gold detection that would allow mineral exploration companies to test for gold on-site at the drilling rig.

Using light in two different processes (fluorescence and absorption), the researchers from the University’s Institute for Photonics and Advanced Sensing (IPAS), have been able to detect gold nanoparticles at detection limits 100 times lower than achievable under current methods.

An April 29, 2015 University of Adelaide news release details Australia’s interest in gold and offers a high level explanation of the need for better gold detection (Note: Links have been removed),

Australia is the world’s second largest gold producer, worth $13 billion in export earnings.

“Gold is not just used for jewellery, it is in high demand for electronics and medical applications around the world, but exploration for gold is extremely challenging with a desire to detect very low concentrations of gold in host rocks,” says postdoctoral researcher Dr Agnieszka Zuber, working on the project with Associate Professor Heike Ebendorff-Heidepriem.

“The presence of gold deep underground is estimated by analysis of rock particles coming out of the drilling holes. But current portable methods for detection are not sensitive enough, and the more sensitive methods require some weeks before results are available.

“This easy-to-use sensor will allow fast detection right at the drill rig with the amount of gold determined within an hour, at much lower cost.”

The researchers have been able to detect less than 100 parts per billion of gold in water. They are now testing using samples of real rock with initial promising results. The work is funded by the Deep Exploration Technologies Cooperative Research Centre.

The gold detection project is one of a series of projects which will be presented at the IPAS Minerals and Energy Sector Workshop today [April 29, 2015], aimed at linking resources specific research to local companies.

You can find out more about the University of Adelaide’s Institute of Photonics and Advanced Sensing here.

Australians inspired by Lycurgus Cup

The Lycurgus Cup is one of the great artistic achievements in history and there’s a nanotechnology twist to this art work created in the 4th century CE (or AD). From the Nov. 21, 2013 news item on Nanowerk,

A 1700-year-old Roman glass cup is inspiring University of Adelaide [Australia] researchers in their search for new ways to exploit nanoparticles and their interactions with light.

Researchers in the University’s Institute for Photonics and Advanced Sensing (IPAS) are investigating how to best embed nanoparticles in glass – instilling the glass with the properties of the nanoparticles it contains.

Before going further with this latest work at the University of Adelaide, here’s an excerpt from my Sept. 21, 2010 posting where I burbled on about the best of piece of writing I’ve seen about the Lycurgus Cup (held in the British Museum),

The *History of the Ancient World website (as Nov. 21, 2013 the link has been changed to the Université de Strasbourg,, Matière Condensée et Nanophysique website) recently featured a 2007 article about the Lycurgus Cup by Ian Freestone, Nigel Meeks, Margaret Sax and Catherine Higgitt for the Gold Bulletin, Vol. 40:4 (2007),

The Lycurgus Cup represents one of the outstanding achievements of the ancient glass industry. This late Roman cut glass vessel is extraordinary in several respects, firstly in the method of fabrication and the exceptional workmanship involved and secondly in terms of the unusual optical effects displayed by the glass.

The Lycurgus Cup is one of a class of Roman vessels known as cage cups or diatreta, where the decoration is in openwork which stands proud from the body of the vessel, to which it is linked by shanks or bridges Typically these openwork “cages” comprise a lattice of linked circles, but a small number have figurative designs, although none of these is as elaborate or as well preserved as the Lycurgus Cup. Cage cups are generally dated to the fourth century A.D. and have been found across the Roman Empire, but the number recovered is small, and probably only in the region of 50-100 examples are known. They are among the most technically sophisticated glass objects produced before the modern era.

Here’s what it looks like,

The Lycurgus Cup 1958,1202.1 in reflected light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

The Lycurgus Cup 1958,1202.1 in reflected light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

And this, too, is the one and only Lycurgus Cup,

The Lycurgus Cup 1958,1202.1 in transmitted light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

The Lycurgus Cup 1958,1202.1 in transmitted light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

The Nov. 21, 2013 University of Adelaide, news release, which originated the news item, explains why the Lycurgus Cup is of such interest, and why the same cup can be green or red

The Lycurgus Cup, a 4th century cup held by the British Museum in London, is made of glass which changes colour from red to green depending on whether light is shining through the Cup or reflected off it. It gets this property from gold and silver nanoparticles embedded in the glass.

“The Lycurgus Cup is a beautiful artefact which, by accident, makes use of the exciting properties of nanoparticles for decorative effect,” says Associate Professor Ebendorff-Heidepriem. “We want to use the same principles to be able to use nanoparticles for all sorts of exciting advanced technologies.”

Nanoparticles need to be held in some kind of solution. “Glass is a frozen liquid,” says Associate Professor Ebendorff-Heidepriem. “By embedding the nanoparticles in the glass, they are fixed in a matrix which we can exploit.”

Associate Professor Ebendorff-Heidepriem is leading a three-year Australian Research Council Discovery Project to investigate how best to embed nanoparticles; looking at the solubility of different types of nanoparticles in glass and how this changes with temperature and glass type, and how the nanoparticles are controlled and modified.

Practical applications, according to the news release, include,

“Nanoparticles and nanocrystals are the focus of research around the world because of their unique properties that have the potential to bring great advances in a wide range of medical, optical and electronic fields,” says Associate Professor Heike Ebendorff-Heidepriem, Senior Research Fellow in the University’s School of Chemistry and Physics. “A process for successfully incorporating nanoparticles into glass, will open the way for applications like ultra low-energy light sources, more efficient solar cells or advanced sensors that can see inside the living human brain.”

“We will be able to more readily harness these nanoscale properties in practical devices. This gives us a tangible material with nanoparticle properties that we can shape into useful forms for real-world applications. And the unique properties are actually enhanced by embedding in glass.”