Tag Archives: Flinders University

Improving bacteria detection with the ‘unboil an egg’ machine

Vortex Fluidic Device (VFD) is the technical name for the more familiarly known ‘unboil an egg machine’ and, these days, it’s being used in research to improve bacteria detection. A June 23, 2020 news item on Nanowerk announces the research (Note: A link has been removed),

The versatility of the Vortex Fluidic Device (VFD), a device that famously unboiled an egg, continues to impress, with the innovative green chemistry device created at Flinders University having more than 100 applications – including the creation of a new non-toxic fluorescent dye that detects bacteria harmful to humans.

Traditional fluorescent dyes to examine bacteria viability are toxic and suffer poor photostability – but using the VFD has enabled the preparation of a new generation of aggregation-induced emission dye (AIE) luminogens using graphene oxide (GO), thanks to collaborative research between Flinders University’s Institute for NanoScale Science and Technology and the Centre for Health Technologies, University of Technology Sydney.

Using the VFD to produce GO/AIE probes with the property of high fluorescence is without precedent – with the new GO/AIE nanoprobe having 1400% brighter high fluorescent performance than AIE luminogen alone (Materials Chemistry Frontiers, “Vortex fluidic enabling and significantly boosting light intensity of graphene oxide with aggregation induced emission luminogen”).

A June 24, 2020 Flinders University [Australia] press release, which originated the news item, delves further into the work,

“It’s crucial to develop highly sensitive ways of detecting bacteria that pose a potential threat to humans at the early stage, so health sectors and governments can be informed promptly, to act quickly and efficiently,” says Flinders University researcher Professor Youhong Tang.

“Our GO/AIE nanoprobe will significantly enhance long-term tracking of bacteria to effectively control hospital infections, as well as developing new and more efficient antibacterial compounds.”

The VFD is a new type of chemical processing tool, capable of instigating chemical reactivity, enabling the controlled processing of materials such as mesoporous silica, and effective in protein folding under continuous flow, which is important in the pharmaceutical industry. It continues to impress researchers for its adaptability in green chemistry innovations.

“Developing such a deep understanding of bacterial viability is important to revise infection control policies and invent effective antibacterial compounds,” says lead author of the research, Dr Javad Tavakoli, a previous researcher from Professor Youhong Tang’s group, and now working at the University of Technology Sydney.

“The beauty of this research was developing a highly bright fluorescence dye based on graphene oxide, which has been well recognised as an effective fluorescence quenching material.”

The type of AIE luminogen was first developed in 2015 to enable long-term monitoring of bacterial viability, however, increasing its brightness to increase sensitivity and efficiency remained a difficult challenge. Previous attempts to produce AIE luminogen with high brightness proved very time-consuming, requires complex chemistry, and involves catalysts rendering their mass production expensive.

By comparison, the Vortex Fluidic Device allows swift and efficient processing beyond batch production and the potential for cost-effective commercialisation.

Increasing the fluorescent property of GO/AIE depends on the concentration of graphene oxide, the rotation speed of the VFD tube, and the water fraction in the compound – so preparing GO/AIE under the shear stress induced by the VFD’s high-speed rotating tube resulted in much brighter probes with significantly enhanced fluorescent intensities.

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

Vortex fluidic enabling and significantly boosting light intensity of graphene oxide with aggregation induced emission luminogen by Javad Tavakoli, Nikita Joseph, Clarence Chuah, Colin L. Raston and Youhong Tang. Mater. Chem. Front., [Materials Chemistry Frontiers] 2020, Advance Article DOI: https://doi.org/10.1039/D0QM00270D First published: 28 May 2020

This paper is behind a paywall.

I first marveled about the VFD (unboil an egg machine) in a March 16, 2016 posting.

Nanotechnology in the house; a guide to what you already have

A July 4, 2016 essay by Cameron Shearer of Flinders University (Australia) on The Conversation website describes how nanotechnology can be found in our homes (Note: Links have been removed),

All kitchens have a sink, most of which are fitted with a water filter. This filter removes microbes and compounds that can give water a bad taste.

Common filter materials are activated carbon and silver nanoparticles.

Activated carbon is a special kind of carbon that’s made to have a very high surface area. This is achieved by milling it down to a very small size. Its high surface area gives more room for unwanted compounds to stick to it, removing them from water.

The antimicrobial properties of silver makes it one of the most common nanomaterials today. Silver nanoparticles kill algae and bacteria by releasing silver ions (single silver atoms) that enter into the cell wall of the organisms and become toxic.

It is so effective and fashionable that silver nanoparticles are now used to coat cutlery, surfaces, fridges, door handles, pet bowls and almost anywhere else microorganisms are unwanted.

Other nanoparticles are used to prepare heat-resistant and self-cleaning surfaces, such as floors and benchtops. By applying a thin coating containing silicon dioxide or titanium dioxide nanoparticles, a surface can become water repelling, which prevents stains (similar to how scotch guard protects fabrics).

Nanoparticle films can be so thin that they can’t be seen. The materials also have very poor heat conductivity, which means they are heat resistant.

The kitchen sink (or dishwasher) is used for washing dishes with the aid of detergents. Detergents form nanoparticles called micelles.

A micelle is formed when detergent molecules self-assemble into a sphere. The centre of this sphere is chemically similar to grease, oils and fats, which are what you want to wash off. The detergent traps oils and fats within the cavity of the sphere to separate them from water and aid dish washing.

Your medicine cabinet may include nanotechnology similar to micelles, with many pharmaceuticals using liposomes.

A liposome is an extended micelle where there is an extra interior cavity within the sphere. Making liposomes from tailored molecules allows them to carry therapeutics inside; the outside of the nanoparticle can be made to target a specific area of the body.

Shearer’s essay goes on to cover the laundry, bathroom, closets, and garage. (h/t July 5, 2016 news item on phys.org)

Unboiling egg technology can cut through carbon nanotubes

One of 2015’s big science stories, Flinders University’s ‘egg unboiler’ (also known as, a vortex fluidic device). has made the news again in a March 11, 2016 news item on phys.org,

Technology used by scientists to unboil an egg is being adapted to precisely cut through carbon nanotubes used in solar panel manufacturing and cancer treatment.

Scientists from Flinders University in South Australia have proven their Vortex Fluidic Device’s ability to slice through carbon nanotubes with great precision.

A March 11, 2016 story written by Caleb Radford for The Lead, which originated the news item, notes the advantages to using this technology for slicing carbon nanotubes (CNTs) and prospects for commercialization,

Device creator and Flinders University Professor Colin Raston said the carbon nanotubes could be commercialised within 12 months.

“Importantly for this technology is that we have uniformity in products,” he said.

“It opens it up for applications in drug delivery if you can get all of the carbon nanotubes to about 100 nanometres … 100 nanometres is the ideal length for getting into tumours so you can actually functionalise them to target cancer cells.

“Uniformity in products also means that you can improve the solar cell efficiency in solar cell devices.”

Flinders University scientists last year were awarded an Ig Nobel Award for creating the Vortex Fluidic Device and using it to unboil an egg.

The device can also be used to slice CNTs accurately to an average length of 170 nanometres using only water, a solvent and a laser.

It is also a simpler and cheaper process than previous methods, which resulted in random lengths that made it difficult to deliver drugs to patients and transfer electrons for solar panel manufacturing.

Flinders University PhD student Kasturi Vimalanathan, who played a key role in discovering new applications for the device, said the machines ability to cut carbon nanotubes to a similar length significantly increased the efficiency of solar cells.

“They shorten the carbon nanotubes to fit in all the chemicals so it can withstand high temperatures,” she said.

“It increases the efficiency and enhances the photoelectric conversion because they can provide a shorter transportation pathway for these electrons.

“It’s a one step method we can scale up. We can see cheaper solar panels on the back of this development.”

Here’s an image of Ralston, presumably with his Vortex Fluidic Device,

Professor Colin Raston received global attention and won an Ig Nobel prize on his way to becoming one of the biggest science stories of 2015. Courtesy Flinders University, Australia

Professor Colin Raston received global attention and won an Ig Nobel prize on his way to becoming one of the biggest science stories of 2015. Courtesy Flinders University, Australia

A Dec. 18, 2015 Flinders University blog posting announced Ralston’s Ig Nobel,

When Flinders University’s Professor Colin Raston unboiled an egg earlier this year with his ‘Vortex Fluidic Device’, in a feat previously considered impossible by science, he made TV screens and front pages all over the world, generating a veritable tsunami of ‘eggscellent’ puns.

The global impact of his achievement transformed the softly spoken South Australia Premier’s Professorial Research Fellow in Clean Technology into an internationally recognised figure overnight – and culminated in him receiving a prestigious Ig Nobel prize in September [2015].

In recognition of the massive amount of attention Professor Raston’s achievement received for Australian research, it has today been hailed as one of the top ten weird and wonderful Australian science stories of 2015 by the Australian Science and Media Centre (AusSMC).

Responding to the announcement, Professor Raston said he had been thrilled with the response to his achievement and had been ‘living the dream’ since.

“We were very interested in how the Vortex Fluidic Device might control protein folding, and the breakthrough with my collaborator at UCI, Greg Weiss, simplifies this, in a fraction of the time, minimising waste generation and energy usage. What this amounted to was unboiling an egg,” he said.

Who would have thought a device for unboiling eggs could be used to cut carbon nanotubes? Clearly, Kasturi Vimalanathan. Amazing.

For anyone interested and/or unfamiliar with the Ig Nobel prizes, there’s my Sept. 17, 2013 posting.

Windows as solar cells using carbon nanotubes from Australia

It’s not a brand new idea (windows as solar cells) as the folks at Flinders University (Adelaide, South Australia) might have you believe but it’s the first time I can recall coming across a reference to carbon nanotubes and ‘solar cell’ windows. From the March 20, 2012 news item on Nanowerk,

As part of his just-completed PhD, Dr Mark Bissett [photograph with Nanowerk news item] from the School of Chemical and Physical Sciences [Flinders University] has developed a revolutionary solar cell using carbon nanotubes.

A promising alternative to traditional silicon-based solar cells, carbon nanotubes are cheaper to make and more efficient to use than their energy-sapping, silicon counterparts.

“The overall efficiency of silicon solar cells are about 10 per cent and even when they’re operating at optimal efficiency it could take eight to 15 years to make back the energy that it took to produce them in the first place because they’re produced using fossil fuels,” he said.

Dr Bissett said the new, low-cost carbon nanotubes are transparent, meaning they can be “sprayed” onto windows without blocking light, and they are also flexible so they can be weaved into a range of materials including fabric – a concept that is already being explored by advertising companies.

While the amount of power generated by solar windows would not be enough to completely offset the energy consumption of a standard office building, Dr Bissett said they still had many financial and environmental advantages.

“In a new building, or one where the windows are being replaced anyway, adding transparent solar cells to the glass would be a relatively small cost since the cost of the glass, frames and installation would be the same with or without the solar component,” Dr Bissett said.

The researchers are suggesting that this technology could be in the marketplace in 10 years.