Archive for August, 2009
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August 31st, 2009
“Gold nanotech breath test may show lung cancer early”
The title of this post is a claim made in this article. Interesting piece of research, but the result that it ‘detected lung cancer with 86 percent accuracy’ suggests there is some way to go before it is a viable clinical method…….
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August 28th, 2009
Carbon nanotubes and toxicity – can gold lend a hand?
Carbon nanotubes (CNTs) are truly extraordinary materials. Many of you reading this will already know a fair bit about them I’m sure, but for those that don’t I suggest you take a quick look at this page which summarises their uses and potential well. There have, however, always been concerns about potential toxicity of these nanomaterials – because of their diminutive size, CNTs have been shown to be able to accumulate in cells, eventually leading to cell death.
This is clearly a significant issue for utilising CNTs in certain fields. One such field in molecular therapeutics and imaging – indeed CNTs have been shown to hold great promise as contrast agents for photoacoustic detection and photothermal killing of individual bacteria in blood system. However, they were never fully developed as such because of the ongoing concerns around toxicity…
It’s for this reason I was impressed by this recent publication in Nature Nanotechnology. The team, led by Jin-Woo Kim and Vladimir Zharov of the University of Arkansas, have addressed this problem by depositing a thin layer of gold around the carbon nanotubes. The gold layer enhanced absorption of laser radiation and reduced toxicity. In vitro tests showed only minimal toxicity associated with the golden nanotubes. Compared to existing nanoparticles, the golden nanotubes also exhibited high laser absorption at a miniscule diameter. The golden nanotubes required extremely low laser-energy levels for detection, and low concentrations were required for effective diagnostic and therapeutic applications.
For more information see the University of Arkansas press release
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August 27th, 2009
Gold: The High Reliability Choice in Semiconductor Packaging
At the IMAPS 2009 event, there is a special invited session on Intelligent Uses of Precious Metals in Microelectronics. With Lee Levine from Process Solutions Consulting, I’ll be presenting the case for why gold remains the high reliability choice in semiconductor packaging, a summary of which appears here.
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August 26th, 2009
Gold-related publications (part 2!)
Following on from my post yesterday I was impressed to find yet more innovative gold research published in another high level chemistry journal. On this occasion the latest issue of Nature Chemistry carries two interesting gold articles, one of which even graces the front cover…
Professor Vince Rotello’s team from the University of Massachusetts have penned a fascinating paper entitled “Sensing of proteins in human serum using conjugates of nanoparticles and green fluorescent protein”, which has made the cover of this issue of Nature Chemistry for good reason. The paper describes the group’s progress in the development of a gold nanoparticle-based sensor system capable of detecting specific proteins at biorelevant concentrations in both buffer and human serum. Being able to detect protein imbalances in serum is an important tool for disease diagnosis, but complicated because it contains >20,000 different proteins at a vast range of concentrations. The science described by Rotello’s team represents highly sensitive array-based sensor system, and a significant improvement on previous polymer-based sensor arrays.
The second paper in this issue of Nature Chemistry is from the labs of Dean Toste at the University of California and William Goddard III at CalTech. They propose a bonding model for gold(1) carbene complexes, where the carbon-gold bond in the cationic intermediates comprise varying degrees of both σ- and π-bonding. The paper then describes a series of experiments that illustrate the correlation between bonding and reactivity is reflected in the yield of gold-catalysed cyclopropanation reactions.
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August 25th, 2009
Gold-related publications
Whilst taking a look at some of the recent literature I noticed three quite diverse gold-based papers in the current issue of the Journal of the American Chemical Society.
The first was from Dean Toste’s group at the University of California. In this brief communication the team describe the development (and potential mechanism) of a gold-catalysed [3+3]-cycloaddition reaction of propargyl esters and azomethine imines. Such reactions provide a rapid entry into a wide range of substituted tetrahydropyridazine derivatives from simple starting materials.
The second paper is from Francis Zamborini at the University of Louisville. Here the team have demonstrated control over the location of anti-immunoglobulin G (anti-IgG) proteins bound to gold nanoplates formed on glass and silicon samples. They then showed that when the anti-IgG proteins were selectively bound to the edge sites (rather than randomly attached to the terraced regions), they exhibited significantly larger changes in the absorbance and wavelength of maximum absorbance of their localized surface plasmon resonance (LSPR) response upon binding. This led to at least 500 times more sensitive detection of IgG down to 0.1 ng/mL.
Finally, there was an excellent paper from Keith Woo’s team at Iowa State describing the use of gold powder in the promotion of organic coupling reactions. This is significant as the particles used ranged from 5 to 50 µm in diameter, far larger than the nanoparticulates generally employed in such reactions. The team showed that the surface morphology significantly affected the reactivity, with smoother particles giving an improved reaction profile.
Seeing three such diverse, gold-related publications in one of the world’s most respected journals clearly illustrates the growing interest in the applications of gold in the chemical sciences.
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August 24th, 2009
Gold nanoparticle researchers win coveted awards
Elena Shevchenko, a researcher at the Argonne National Laboratory, and C. Shad Thaxton of Northwestern University have both been awarded the 2009 Technology Review Young Innovator of the year award.
Dr Shevchenko is recognised for her significant contributions in the field of nanocrystallisation and material research. Her work has led to new methods for the synthesis of metallic nanoparticles, and the assembly of those nanoparticles into ordered ‘superlattices’ which display a range of commercially useful properties. Dr Shevchenko has published extensively (for examples see here and here).Dr Thaxton’s work centres on the use of gold nanoparticles to mimic HDL (com
monly known as “good” cholesterol). HDL is a complex protein which works by delivering cholesterol to the liver for excretion. Dr Thaxton has synthesised gold nanoparticles which are coated with specific proteins and fats enabling them to ‘stick’ to cholesterol, thus mimicking the effect of HDL in the body. This work is described in more detail here.Congratulations to both Dr Shevchenko and Dr Thaxton on receiving these prestigious awards.
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August 21st, 2009
Accelerating commercialisation
Michael Kenward at ScienceBusiness highlights some interesting recent comments from Tom Hockaday, the Managing Director of Isis Innovation Ltd, the wholly owned technology transfer subsidiary of Oxford University. Isis is one of the UK’s best university technology transfer offices, with multiple commercially successful spin-out companies and numerous technologies brought to market.
I’ll leave you to read the detail of the two articles but one of the main thrusts is that it is pointless to bully researchers who simply don’t want to be involved in technology transfer. In other words, not all academics with interesting science want to commercialise technology. From our perspective at World Gold Council this really rings true. An interesting scientific paper that identifies a possible new use of gold may, or may not, be worthy of our efforts to pursue further feasibility studies. It largely depends on the researcher involved and whether they are really serious about trying to bring a new (gold-based) technology to commercial markets or whether they are really just looking for the next funds to deliver a new paper for a leading research journal.
Why do I mention this? Well, our GROW Programme is very much about forming partnerships to facilitate and accelerate commercialisation. World Gold Council recognises that new gold science is the foundation upon which new technologies will eventually emerge (it’s why we publish Gold Bulletin for example), but our role is not to fund basic (gold) research. Our role is to help support and accelerate the rate at which gold technologies eventually reach the market.
Those interested in the GROW Programme should consider this when making an application to us……
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August 20th, 2009
Nanoparticles 2009
I’m looking forward to attending the Nanoparticles 2009 meeting in Liverpool in early September. The organisers of this RSC/SCI sponsored meeting have brought together a really strong programme of presentations covering the synthesis, properties and applications of nanoparticles. There is even a presentation from Andrew Miller MP discussing parliament’s understanding of science.If any of our readers are attending the event and would like to meet to discuss the World Gold Council’s support of nanotechnology research through our GROW programme please drop me a line.
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August 19th, 2009
Significant ‘nanolaser’ breakthrough announced
Researchers in the United States have just published an article unveiling the world’s smallest laser, a breakthrough which could be key to future optical computers and technologies.
The laser itself is contained in a silica-coated gold nanoparticle measuring a mere 44nm in diameter. In fact the term ‘laser’ is in fact a misnomer within this system, as it is not light which is being amplified, but the plasmons on the surface of the gold. As such, the term ‘spaser‘ has been coined.
The real excitement that goes along with this announcement is the potential for future technologies. Numerous areas have already been highlighted, such as the tagging of large biochemical assays, security markings and ultrafast nanoelectronics.
Matthew Chalmers has written an excellent piece on the announcement for Nature News which contains more information.
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August 18th, 2009
Superconducting and Element 79
I really like some of the technology perspectives offered by the Scientist NZ blog.
This one, on superconductivity, reminded me of some work World Gold Council carried out looking at gold’s use in this field. In turns out that in one use of superconductors (in the fault current limiters application), the most recent generation of materials that are able to operate at higher temperatures, such as YBCO (YBa2Cu3O7), require the use of a metallic shunt top layer to give a degree of thermal and electrical protection should a fault in the superconducting tape develop. This metallic layer is typically 50-100nm thick and must be resistant to oxidation at the high temperatures which can arise during both processing steps and in service during current overload situation. It must also serve as a barrier to prevent ingress of moisture into the YBCO superconductor.
We found research that showed that sputtered silver, gold and silver-gold alloy layers have so far shown the best combination of properties for this applications including electrical and thermal conductivities, contact resistance, specific heat capacities, oxidation potential, lattice constant, and coefficient of linear expansion (High-power-density fault-current limiting devices using YBa2Cu3O7 superconducting films and high resistivity alloy shunt layers, H Yamasaki, M Furuse and Y Nakagawa, Appl. Phys. Lett., 2004, 85, 4427)
By the way, the superconducting properties of gold intermetallics themselves were reviewed by Khan and Raub in Gold Bulletin, although no intermetallic compound of gold has yet been found to exhibit sufficient superconductivity to make it industrially interesting.
Richard Holliday
Trevor Keel
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