Tag Archives: spectroscopy

Faster diagnostics with nanoparticles and magnetic phenomenon discovered 170 years ago

A Jan. 19, 2017 news item on ScienceDaily announces some new research from the University of Central Florida (UCF),

A UCF researcher has combined cutting-edge nanoscience with a magnetic phenomenon discovered more than 170 years ago to create a method for speedy medical tests.

The discovery, if commercialized, could lead to faster test results for HIV, Lyme disease, syphilis, rotavirus and other infectious conditions.

“I see no reason why a variation of this technique couldn’t be in every hospital throughout the world,” said Shawn Putnam, an assistant professor in the University of Central Florida’s College of Engineering & Computer Science.

A Jan. 19, 2017 UCF news release by Mark Schlueb, which originated the news item,  provides more technical detail,

At the core of the research recently published in the academic journal Small are nanoparticles – tiny particles that are one-billionth of a meter. Putnam’s team coated nanoparticles with the antibody to BSA, or bovine serum albumin, which is commonly used as the basis of a variety of diagnostic tests.

By mixing the nanoparticles in a test solution – such as one used for a blood test – the BSA proteins preferentially bind with the antibodies that coat the nanoparticles, like a lock and key.

That reaction was already well known. But Putnam’s team came up with a novel way of measuring the quantity of proteins present. He used nanoparticles with an iron core and applied a magnetic field to the solution, causing the particles to align in a particular formation. As proteins bind to the antibody-coated particles, the rotation of the particles becomes sluggish, which is easy to detect with laser optics.

The interaction of a magnetic field and light is known as Faraday rotation, a principle discovered by scientist Michael Faraday in 1845. Putnam adapted it for biological use.

“It’s an old theory, but no one has actually applied this aspect of it,” he said.

Other antigens and their unique antibodies could be substituted for the BSA protein used in the research, allowing medical tests for a wide array of infectious diseases.

The proof of concept shows the method could be used to produce biochemical immunology test results in as little as 15 minutes, compared to several hours for ELISA, or enzyme-linked immunosorbent assay, which is currently a standard approach for biomolecule detection.

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

High-Throughput, Protein-Targeted Biomolecular Detection Using Frequency-Domain Faraday Rotation Spectroscopy by Richard J. Murdock, Shawn A. Putnam, Soumen Das, Ankur Gupta, Elyse D. Z. Chase, and Sudipta Seal. Small DOI: 10.1002/smll.201602862 Version of Record online: 16 JAN 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Functional hybrid system that can connect human tissue with electronic devices

I’ve tagged this particular field of interest ‘machine/flesh’ because I find it more descriptive than ‘bio-hybrid system’ which was the term used in a Nov. 15, 2016 news item on phys.org,

One of the biggest challenges in cognitive or rehabilitation neurosciences is the ability to design a functional hybrid system that can connect and exchange information between biological systems, like neurons in the brain, and human-made electronic devices. A large multidisciplinary effort of researchers in Italy brought together physicists, chemists, biochemists, engineers, molecular biologists and physiologists to analyze the biocompatibility of the substrate used to connect these biological and human-made components, and investigate the functionality of the adhering cells, creating a living biohybrid system.

A Nov.15, 2016 American Institute of Physics news release on EurekAlert, which originated the news item, details the investigation,

In an article appearing this week in AIP Advances, from AIP Publishing, the research team used the interaction between light and matter to investigate the material properties at the molecular level using Raman spectroscopy, a technique that, until now, has been principally applied to material science. Thanks to the coupling of the Raman spectrometer with a microscope, spectroscopy becomes a useful tool for investigating micro-objects such as cells and tissues. Raman spectroscopy presents clear advantages for this type of investigation: The molecular composition and the modi?cation of subcellular compartments can be obtained in label-free conditions with non-invasive methods and under physiological conditions, allowing the investigation of a large variety of biological processes both in vitro and in vivo.

Once the biocompatibility of the substrate was analyzed and the functionality of the adhering cells investigated, the next part of this puzzle is connecting with the electronic component. In this case a memristor was used.

“Its name reveals its peculiarity (MEMory ResISTOR), it has a sort of “memory”: depending on the amount of voltage that has been applied to it in the past, it is able to vary its resistance, because of a change of its microscopic physical properties,” said Silvia Caponi, a physicist at the Italian National Research Council in Rome. By combining memristors, it is possible to create pathways within the electrical circuits that work similar to the natural synapses, which develop variable weight in their connections to reproduce the adaptive/learning mechanism. Layers of organic polymers, like polyaniline (PANI) a semiconductor polymer, also have memristive properties, allowing them to work directly with biological materials into a hybrid bio-electronic system.

“We applied the analysis on a hybrid bio-inspired device but in a prospective view, this work provides the proof of concept of an integrated study able to analyse the status of living cells in a large variety of applications that merges nanosciences, neurosciences and bioelectronics,” said Caponi. A natural long-term objective of this work would be interfacing machines and nervous systems as seamlessly as possible.

The multidisciplinary team is ready to build on this proof of principle to realize the potential of memristor networks.

“Once assured the biocompatibility of the materials on which neurons grow,” said Caponi, “we want to define the materials and their functionalization procedures to find the best configuration for the neuron-memristor interface to deliver a full working hybrid bio-memristive system.”

Caption: These are immunofluorescence analysis of SH-SY5Y cells treated for 5 days with 10uM Retinoic Acid and 50ng/ml BDNF for the next 3 days. The DAPI fluorescence stain is blue and Beta-tubulin is green. Credit: Caponi, et al.

Caption: These are immunofluorescence analysis of SH-SY5Y cells treated for 5 days with 10uM Retinoic Acid and 50ng/ml BDNF for the next 3 days. The DAPI fluorescence stain is blue and Beta-tubulin is green. Credit: Caponi, et al.

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

A multidisciplinary approach to study the functional properties of neuron-like cell models constituting a living bio-hybrid system: SH-SY5Y cells adhering to PANI substrate by S. Caponi, S. Mattana, M. Ricci, K. Sagini, L. J. Juarez-Hernandez, A. M. Jimenez-Garduño, N. Cornella, L. Pasquardini, L. Urbanelli, P. Sassi, A. Morresi, C. Emiliani, D. Fioretto, M. Dalla Serra, C. Pederzolli, S. Iannotta, P. Macchi, and C. Musio. AIP Advances 6, 111303 (2016); http://dx.doi.org/10.1063/1.4966587

This paper appears to be open access.

Nano and a Unified Microbiome Initiative (UMI)

A Jan. 6, 2015 news item on Nanowerk features a proposal by US scientists for a Unified Microbiome Initiative (UMI),

In October [2015], an interdisciplinary group of scientists proposed forming a Unified Microbiome Initiative (UMI) to explore the world of microorganisms that are central to life on Earth and yet largely remain a mystery.

An article in the journal ACS Nano (“Tools for the Microbiome: Nano and Beyond”) describes the tools scientists will need to understand how microbes interact with each other and with us.

A Jan. 6, 2016 American Chemical Society (ACS) news release, which originated the news item, expands on the theme,

Microbes live just about everywhere: in the oceans, in the soil, in the atmosphere, in forests and in and on our bodies. Research has demonstrated that their influence ranges widely and profoundly, from affecting human health to the climate. But scientists don’t have the necessary tools to characterize communities of microbes, called microbiomes, and how they function. Rob Knight, Jeff F. Miller, Paul S. Weiss and colleagues detail what these technological needs are.

The researchers are seeking the development of advanced tools in bioinformatics, high-resolution imaging, and the sequencing of microbial macromolecules and metabolites. They say that such technology would enable scientists to gain a deeper understanding of microbiomes. Armed with new knowledge, they could then tackle related medical and other challenges with greater agility than what is possible today.

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

Tools for the Microbiome: Nano and Beyond by Julie S. Biteen, Paul C. Blainey, Zoe G. Cardon, Miyoung Chun, George M. Church, Pieter C. Dorrestein, Scott E. Fraser, Jack A. Gilbert, Janet K. Jansson, Rob Knight, Jeff F. Miller, Aydogan Ozcan, Kimberly A. Prather, Stephen R. Quake, Edward G. Ruby, Pamela A. Silver, Sharif Taha, Ger van den Engh, Paul S. Weiss, Gerard C. L. Wong, Aaron T. Wright, and Thomas D. Young. ACS Nano, Article ASAP DOI: 10.1021/acsnano.5b07826 Publication Date (Web): December 22, 2015

Copyright © 2015 American Chemical Society

This is an open access paper.

I sped through very quickly and found a couple of references to ‘nano’,

Ocean Microbiomes and Nanobiomes

Life in the oceans is supported by a community of extremely small organisms that can be called a “nanobiome.” These nanoplankton particles, many of which measure less than 0.001× the volume of a white blood cell, harvest solar and chemical energy and channel essential elements into the food chain. A deep network of larger life forms (humans included) depends on these tiny microbes for its energy and chemical building blocks.

The importance of the oceanic nanobiome has only recently begun to be fully appreciated. Two dominant forms, Synechococcus and Prochlorococcus, were not discovered until the 1980s and 1990s.(32-34) Prochloroccus has now been demonstrated to be so abundant that it may account for as much as 10% of the world’s living organic carbon. The organism divides on a diel cycle while maintaining constant numbers, suggesting that about 5% of the world’s biomass flows through this species on a daily basis.(35-37)

Metagenomic studies show that many other less abundant life forms must exist but elude direct observation because they can neither be isolated nor grown in culture.

The small sizes of these organisms (and their genomes) indicate that they are highly specialized and optimized. Metagenome data indicate a large metabolic heterogeneity within the nanobiome. Rather than combining all life functions into a single organism, the nanobiome works as a network of specialists that can only exist as a community, therein explaining their resistance to being cultured. The detailed composition of the network is the result of interactions between the organisms themselves and the local physical and chemical environment. There is thus far little insight into how these networks are formed and how they maintain steady-state conditions in the turbulent natural ocean environment.

Rather than combining all life functions into a single organism, the nanobiome works as a network of specialists that can only exist as a community

The serendipitous discovery of Prochlorococcus happened by applying flow cytometry (developed as a medical technique for counting blood cells) to seawater.(34) With these medical instruments, the faint signals from nanoplankton can only be seen with great difficulty against noisy backgrounds. Currently, a small team is adapting flow cytometric technology to improve the capabilities for analyzing individual nanoplankton particles. The latest generation of flow cytometers enables researchers to count and to make quantitative observations of most of the small life forms (including some viruses) that comprise the nanobiome. To our knowledge, there are only two well-equipped mobile flow cytometry laboratories that are regularly taken to sea for real-time observations of the nanobiome. The laboratories include equipment for (meta)genome analysis and equipment to correlate the observations with the local physical parameters and (nutrient) chemistry in the ocean. Ultimately, integration of these measurements will be essential for understanding the complexity of the oceanic microbiome.

The ocean is tremendously undersampled. Ship time is costly and limited. Ultimately, inexpensive, automated, mobile biome observatories will require methods that integrate microbiome and nanobiome measurements, with (meta-) genomics analyses, with local geophysical and geochemical parameters.(38-42) To appreciate how the individual components of the ocean biome are related and work together, a more complete picture must be established.

The marine environment consists of stratified zones, each with a unique, characteristic biome.(43) The sunlit waters near the surface are mixed by wind action. Deeper waters may be mixed only occasionally by passing storms. The dark deepest layers are stabilized by temperature/salinity density gradients. Organic material from the photosynthetically active surface descends into the deep zone, where it decomposes into nutrients that are mixed with compounds that are released by volcanic and seismic action. These nutrients diffuse upward to replenish the depleted surface waters. The biome is stratified accordingly, sometimes with sudden transitions on small scales. Photo-autotrophs dominate near the surface. Chemo-heterotrophs populate the deep. The makeup of the microbial assemblages is dictated by the local nutrient and oxygen concentrations. The spatiotemporal interplay of these systems is highly relevant to such issues as the carbon budget of the planet but remains little understood.

And then, there was this,

Nanoscience and Nanotechnology Opportunities

The great advantage of nanoscience and nanotechnology in studying microbiomes is that the nanoscale is the scale of function in biology. It is this convergence of scales at which we can “see” and at which we can fabricate that heralds the contributions that can be made by developing new nanoscale analysis tools.(159-168) Microbiomes operate from the nanoscale up to much larger scales, even kilometers, so crossing these scales will pose significant challenges to the field, in terms of measurement, stimulation/response, informatics, and ultimately understanding.

Some progress has been made in creating model systems(143-145, 169-173) that can be used to develop tools and methods. In these cases, the tools can be brought to bear on more complex and real systems. Just as nanoscience began with the ability to image atoms and progressed to the ability to manipulate structures both directly and through guided interactions,(162, 163, 174-176) it has now become possible to control structure, materials, and chemical functionality from the submolecular to the centimeter scales simultaneously. Whereas substrates and surface functionalization have often been tailored to be resistant to bioadhesion, deliberate placement of chemical patterns can also be used for the growth and patterning of systems, such as biofilms, to be put into contact with nanoscale probes.(177-180) Such methods in combination with the tools of other fields (vide infra) will provide the means to probe and to understand microbiomes.

Key tools for the microbiome will need to be miniaturized and made parallel. These developments will leverage decades of work in nanotechnology in the areas of nanofabrication,(181) imaging systems,(182, 183) lab-on-a-chip systems,(184) control of biological interfaces,(185) and more. Commercialized and commoditized tools, such as smart phone cameras, can also be adapted for use (vide infra). By guiding the development and parallelization of these tools, increasingly complex microbiomes will be opened for study.(167)

Imaging and sensing, in general, have been enjoying a Renaissance over the past decades, and there are various powerful measurement techniques that are currently available, making the Microbiome Initiative timely and exciting from the broad perspective of advanced analysis techniques. Recent advances in various -omics technologies, electron microscopy, optical microscopy/nanoscopy and spectroscopy, cytometry, mass spectroscopy, atomic force microscopy, nuclear imaging, and other techniques, create unique opportunities for researchers to investigate a wide range of questions related to microbiome interactions, function, and diversity. We anticipate that some of these advanced imaging, spectroscopy, and sensing techniques, coupled with big data analytics, will be used to create multimodal and integrated smart systems that can shed light onto some of the most important needs in microbiome research, including (1) analyzing microbial interactions specifically and sensitively at the relevant spatial and temporal scales; (2) determining and analyzing the diversity covered by the microbial genome, transcriptome, proteome, and metabolome; (3) managing and manipulating microbiomes to probe their function, evaluating the impact of interventions and ultimately harnessing their activities; and (4) helping us identify and track microbial dark matter (referring to 99% of micro-organisms that cannot be cultured).

In this broad quest for creating next-generation imaging and sensing instrumentation to address the needs and challenges of microbiome-related research activities comprehensively, there are important issues that need to be considered, as discussed below.

The piece is extensive and quite interesting, if you have the time.

Speed of commercializing fashion technology in the 19th century

It took our 19th century ancestors four years to commercialize a new purple dye. While this is not a nanotechnology story as such, it’s a fascinating fashion story that also focuses on commercialization (a newly urgent aspect of the nanotechnology effort). From a Dec. 1, 2015 Elsevier press release on EurekAlert,

The dye industry of the 19th century was fast-moving and international, according to a state-of-the-art analysis of four purple dresses. The study, published in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy, reveals that a brand new purple dye went from first synthesis to commercial use in just a few years.

Before the 1800s, purple dye came at a premium, so it was usually restricted to royalty — hence the connection between royals and purple. The 19th century saw the discovery of several synthetic purple dyes, making purple textiles more affordable and readily available. Understanding where these dyes came from and were used is therefore of historical interest.

In the new study, researchers from CSIRO Manufacturing and the National Gallery of Victoria in Australia show that the new purple dyes were part of a fast-moving industry, going from first synthesis to commercial use in as few as four years. This reflects how dynamic the fashion industry must have been at the time.

“Chemical analysis has given us a glimpse into the state of the dye industry in the 19th century, revealing the actual use of dyes around the world,” said Dr. Jeffrey Church, one of the authors of the study and principal research scientist at CSIRO Manufacturing.

The researchers took small samples of fibers from four dresses: three 19th century English dresses and one Australian wedding gown. They extracted the dyes from very small silk yarn samples and analyzed them using a combination of chemical techniques: thin layer chromatography and surface enhanced Raman spectroscopy, Fourier transform infrared spectroscopy and energy dispersive x-ray spectroscopy.

They found that the three English dresses were dyed using methyl violet; one of them was made only four years after the dye was first synthesized.

“The dress containing methyl violet was made shortly after the initial synthesis of the dye, indicating the rapidity with which the new synthetic dyes were embraced by the textile dye trade and the fashion world of the day,” commented Dr. Church.

However, the Australian wedding dress incorporated the use of a different dye — Perkin’s mauve — which was very historically significant, as it was the first synthetic purple dye and was only produced for 10 years. This was a surprise to the researchers, as the dress was made 20 years after the dye had been replaced on the market.

“The dress in question was made in Australia,” explained Dr. Church. “Does the presence of Perkin’s mauve relate to trade delays between Europe and Australia? Or was this precious fabric woven decades earlier and kept for the special purpose of a wedding? This is an excellent example of how state-of-the-art science and technology can shed light on the lives and times of previous generations. In doing so, as is common in science, one often raises more questions.”

The researchers have provided an image of the dresses,

Fig. 1. Dress 1 circa 1865, dress 2 circa 1898, dress 3 circa 1878 and dress 4 circa 1885 (clock-wise from left top). Details of these dresses are presented in the Experimental section. [downloaded from http://www.sciencedirect.com/science/article/pii/S1386142515302742]

Fig. 1. Dress 1 circa 1865, dress 2 circa 1898, dress 3 circa 1878 and dress 4 circa 1885 (clock-wise from left top). Details of these dresses are presented in the Experimental section. [downloaded from http://www.sciencedirect.com/science/article/pii/S1386142515302742]

Can you guess which one is the wedding dress? I was wrong. To find out more about the research and the dresses, here’s a link and a citation,

The purple coloration of four late 19th century silk dresses: A spectroscopic investigation by Andrea L. Woodhead, Bronwyn Cosgrove, Jeffrey S. Church. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Volume 154, 5 February 2016, Pages 185–192  doi:10.1016/j.saa.2015.10.024

This paper appears to be open access. It’s quite interesting as they trace the history of purple dyes back to ancient times before fast forwarding to the 19th Century.

Art (Lawren Harris and the Group of Seven), science (Raman spectroscopic examinations), and other collisions at the 2014 Canadian Chemistry Conference (part 4 of 4)

Cultural heritage and the importance of pigments and databases

Unlike Thom (Ian Thom, curator at the Vancouver Art Gallery), I believe that the testing was important. Knowing the spectra emitted by the pigments in Hurdy Gurdy and Autumn Harbour could help to set benchmarks for establishing the authenticity of the pigments used by artists (Harris and others) in the early part of Canada’s 20th century.

Europeans and Americans are more advanced in their use of technology as a tool in the process of authenticating, restoring, or conserving a piece of art. At the Chicago Institute of Art they identified the red pigment used in a Renoir painting as per my March 24, 2014 posting,

… The first item concerns research by Richard Van Duyne into the nature of the red paint used in one of Renoir’s paintings. A February 14, 2014 news item on Azonano describes some of the art conservation work that Van Duyne’s (nanoish) technology has made possible along with details about this most recent work,

Scientists are using powerful analytical and imaging tools to study artworks from all ages, delving deep below the surface to reveal the process and materials used by some of the world’s greatest artists.

Northwestern University chemist Richard P. Van Duyne, in collaboration with conservation scientists at the Art Institute of Chicago, has been using a scientific method he discovered nearly four decades ago to investigate masterpieces by Pierre-Auguste Renoir, Winslow Homer and Mary Cassatt.

Van Duyne recently identified the chemical components of paint, now partially faded, used by Renoir in his oil painting “Madame Léon Clapisson.” Van Duyne discovered the artist used carmine lake, a brilliant but light-sensitive red pigment, on this colorful canvas. The scientific investigation is the cornerstone of a new exhibition at the Art Institute of Chicago.

There are some similarities between the worlds of science (in this case, chemistry) and art (collectors,  institutions, curators, etc.). They are worlds where one must be very careful.

The scientists/chemists choose their words with precision while offering no certainties. Even the announcement for the discovery (by physicists) of the Higgs Boson is not described in absolute terms as I noted in my July 4, 2012 posting titled: Tears of joy as physicists announce they’re pretty sure they found the Higgs Boson. As the folks from ProsPect Scientific noted,

This is why the science must be tightly coupled with art expertise for an effective analysis.  We cannot do all of that for David [Robertson]. [He] wished to show a match between several pigments to support an interpretation that the ‘same’ paints were used. The availability of Hurdy Gurdy made this plausible because it offered a known benchmark that lessened our dependency on the databases and art-expertise. This is why Raman spectroscopy more often disproves authenticity (through pigment anachronisms). Even if all of the pigments analysed showed the same spectra we don’t know that many different painters didn’t buy the same brand of paint or that some other person didn’t take those same paints and use them for a different painting. Even if all pigments were different, that doesn’t mean Lawren Harris didn’t paint it, it just means different paints were used.

In short they proved that one of the pigments used in Autumn Harbour was also used in the authenticated Harris, Hurdy Gurdy, and the other pigment was in use at that time (early 20th century) in Canada. It doesn’t prove it’s a Harris painting but, unlike the Pollock painting where they found an anachronistic pigment, it doesn’t disprove Robertson’s contention.

To contrast the two worlds, the art world seems to revel in secrecy for its own sake while the world of science (chemistry) will suggest, hint, or hedge but never state certainties. The ProSpect* Scientific representative commented on authentication, art institutions, and databases,

We know that some art institutions are extremely cautious about any claims towards authentication, and they decline to be cited in anything other than the work they directly undertake. (One director of a well known US art institution said to me that they pointedly do not authenticate works, she offered advice on how to conduct the analysis but declined any reference to her institution.) We cannot comment on any of the business plans of any of our customers but the customers we have that use Raman spectroscopy on paintings generally build databases from their collected studies as a vital tool to their own ongoing work collecting and preserving works of art.

We don’t know of anyone with a database particular to pigments used by Canadian artists and neither did David R. We don’t know that any organization is developing such a database.The database we used is a mineral database (as pigments in the early 20th century were pre-synthetic this database contains some of the things commonly used in pigments at that time) There are databases available for many things:  many are for sale, some are protected intellectual property. We don’t have immediate access to a pigments database. Some of our art institution/museum customers are developing their own but often these are not publicly available. Raman spectroscopy is new on the scene relative to other techniques like IR and X-Ray analysis and the databases of Raman spectra are less mature.

ProSpect Scientific provided two papers which illustrate either the chemists’ approach to testing and art (RAMAN VIBRATIONAL STUDY OF PIGMENTS WITH PATRIMONIAL INTEREST FOR THE CHILEAN CULTURAL HERITAGE) and/or the art world’s approach (GENUINE OR FAKE: A MICRO-RAMAN SPECTROSCOPY STUDY OF AN ABSTRACT PAINTING ATTRIBUTED TO VASILY KANDINSKY [PDF]).

Canadian cultural heritage

Whether or not Autumn Harbour is a Lawren Harris painting may turn out to be less important than establishing a means for better authenticating, restoring, and conserving Canadian cultural heritage. (In a June 13, 2014 telephone conversation, David Robertson claims he will forward the summary version of the data from the tests to the Canadian Conservation Institute once it is received.)

If you think about it, Canadians are defined by the arts and by research. While our neighbours to the south went through a revolutionary war to declare independence, Canadians have declared independence through the visual and literary arts and the scientific research and implementation of technology (transportation and communication in the 19th and 20th centuries).

Thank you to both Tony Ma and David Robertson.

Finally, Happy Canada Day on July 1, 2014!

Part 1

Part 2

Part 3

* ‘ProsPect’ changed to ‘ProSpect’ on June 30, 2014.

ETA July 14, 2014 at 1300 hours PDT: There is now an addendum to this series, which features a reply from the Canadian Conservation Institute to a query about art pigments used by Canadian artists and access to a database of information about them.

Lawren Harris (Group of Seven), art authentication, and the Canadian Conservation Insitute (addendum to four-part series)

Art (Lawren Harris and the Group of Seven), science (Raman spectroscopic examinations), and other collisions at the 2014 Canadian Chemistry Conference (part 3 of 4)

Dramatic headlines (again)

Ignoring the results entirely, Metro News Vancouver, which favours the use of the word ‘fraud’, featured it in the headline of a second article about the testing, “Alleged Group of Seven work a fraud: VAG curator” by Thandi Fletcher (June 5, 2014 print issue); happily the online version of Fletcher’s story has had its headline changed to the more accurate: “Alleged Group of Seven painting not an authentic Lawren Harris, says Vancouver Art Gallery curator.” Fletcher’s article was updated after its initial publication with some additional text (it is worth checking out the online version even if you’re already seen the print version). There had been a second Vancouver Metro article on the testing of the authenticated painting by Nick Wells but that in common, with his June 4, 2014 article about the first test, “A fraud or a find?” is no longer available online. Note: Standard mainstream media practice is that the writer with the byline for the article is not usually the author of the article’s headline.

There are two points to be made here. First, Robertson has not attempted to represent ‘Autumn Harbour’ as an authentic Lawren Harris painting other than in a misguided headline for his 2011 news release.  From Robertson’s July 26, 2011 news release (published by Reuters and published by Market Wired) where he crossed a line by stating that Autumn Harbour is a Harris in his headline (to my knowledge the only time he’s done so),

Lost Lawren Harris Found in Bala, Ontario

Unknown 24×36 in. Canvas Piques a Storm of Controversy

VANCOUVER, BRITISH COLUMBIA–(Marketwire – July 26, 2011) –
Was Autumn Harbour painted by Lawren Harris in the fall of 1912? That summer Lawren Harris was 26 years old and had proven himself as an accomplished and professional painter. He had met J.E.H. MacDonald in November of 1911. They became fast friends and would go on to form the Group of Seven in 1920 but now in the summer of 1912 they were off on a sketching expedition to Mattawa and Temiscaming along the Quebec-Ontario border. Harris had seen the wilderness of the northern United States and Europe but this was potentially his first trip outside the confines of an urban Toronto environment into the Canadian wilderness.

By all accounts he was overwhelmed by what he saw and struggled to find new meaning in his talents that would capture these scenes in oil and canvas. There are only two small works credited to this period, archived in the McMichael gallery in Kleinburg, Ontario. Dennis Reid, Assistant Curator of the National Gallery of Canada stated in 1970 about this period: “Both Harris and (J.E.H.) MacDonald explored new approaches to handling of colour and overall design in these canvases. Harris in particular was experimenting with new methods of paint handling, and Jackson pointed out the interest of the other painters in these efforts, referring to the technique affectionately as ‘Tomato Soup’.” For most authorities the summer and fall of 1912 are simply called his ‘lost period’ because it was common for Harris to destroy, abandon or give away works that did not meet his standards. The other trait common to Harris works, is the lack of a signature and some that are signed were signed on his behalf. The most common proxy signatory was Betsy Harris, his second wife who signed canvases on his behalf when he could no longer do so.

So the question remains. Can an unsigned 24×36 in. canvas dated to 1900-1920 that was found in a curio shop in Bala, Ontario be a long lost Lawren Harris? When pictures were shown to Charles C. Hill, Curator of Canadian Art, National Gallery of Canada, he replied: “The canvas looks like no Harris I have ever seen…” A similar reply also came from Ian Thom, Head Curator for the Vancouver Art Gallery: “I do not believe that your work can be connected with Harris in any way.” [emphases mine] Yet the evidence still persists. The best example resides within the National Art Gallery. A 1919, 50.5 X 42.5 in. oil on rough canvas shows Harris’s style of under painting, broad brush strokes and stilled composition. Shacks, painted in 1919 and acquired the Gallery in 1920 is an exact technique clone of Autumn Harbour. For a list of comparisons styles with known Harris works and a full list of the collected evidence please consult www.1912lawrenharris.ca/ and see for yourself.

If Robertson was intent on perpetrating a fraud, why would he include the negative opinions from the curators or attempt to authenticate his purported Harris? The 2011 website is no longer available but Robertson has established another website, http://autumnharbour.ca/.

It’s not a crime (fraud) to have strong or fervent beliefs. After all, Robertson was the person who contacted ProSpect* Scientific to arrange for a test.

Second, Ian Thom, the VAG curator did not call ‘Autumn Harbour’ or David Robertson, a fraud. From the updated  June 5, 2014 article sporting a new headline by Thandi Fletcher,

“I do not believe that the painting … is in fact a Lawren Harris,” said Ian Thom, senior curator at the Vancouver Art Gallery, “It’s that simple.”

It seems Thom feels as strongly as Robertson does; it’s just that Thom holds an opposing opinion.

Monetary value was mentioned earlier as an incentive for Robertson’s drive to prove the authenticity of his painting, from the updated June 5, 2014 article with the new headline by Thandi Fletcher,

Still, Robertson, who has carried out his own research on the painting, said he is convinced the piece is an authentic Harris. If it were, he said it would be worth at least $3 million. [emphasis mine]

“You don’t have to have a signature on the canvas to recognize brushstroke style,” he said.

Note: In a June 13, 2014 telephone conversation, Robertson used the figure of $1M to denote his valuation of Autumn Harbour and claimed a degree in Geography with a minor in Fine Arts from the University of Waterloo. He also expressed the hope that Autumn Harbour would prove to be a* Rosetta Stone of sorts for art pigments used in the early part of the 20th century.

As for the owner of Hurdy Gurdy and the drama that preceded its test on June 4, 2014, Fletcher had this in her updated and newly titled article,

Robertson said the painting’s owner, local Vancouver businessman Tony Ma, had promised to bring the Harris original to the chemistry conference but pulled out after art curator Thom told him not to participate.

While Thom acknowledged that Ma did ask for his advice, he said he didn’t tell him to pull out of the conference.

“It was more along the lines of, ‘If I were you, I wouldn’t do it, because I don’t think it’s going to accomplish anything,’” said Thom, adding that the final decision is up to Ma. [emphasis mine]

A request for comment from Ma was not returned Wednesday [June 5, 2014].

Thom, who already examined Robertson’s painting a year ago [in 2013? then, how is he quoted in a 2011 news release?], said he has no doubt Harris did not paint it.

“The subject matter is wrong, the handling of the paint is wrong, and the type of canvas is wrong,” he said, adding that many other art experts agree with him.

Part 1

Part 2

Part 4

* ‘ProsPect’ changed to ‘ProSpect’ on June 30, 2014. Minor grammatical change made to sentence: ‘He also expressed the hope that Autumn Harbour would prove to a be of Rosetta Stone of sorts for art pigments used in the early part of the 20th century.’ to ‘He also expressed the hope that Autumn Harbour would prove to be a* Rosetta Stone of sorts for art pigments used in the early part of the 20th century.’ on July 2, 2014.

ETA July 14, 2014 at 1300 hours PDT: There is now an addendum to this series, which features a reply from the Canadian Conservation Institute to a query about art pigments used by Canadian artists and access to a database of information about them.

Lawren Harris (Group of Seven), art authentication, and the Canadian Conservation Insitute (addendum to four-part series)

Art (Lawren Harris and the Group of Seven), science (Raman spectroscopic examinations), and other collisions at the 2014 Canadian Chemistry Conference (part 2 of 4)

Testing the sample and Raman fingerprints

The first stage of the June 3, 2010 test of David Robertson’s Autumn Harbour, required taking a tiny sample from the painting,. These samples are usually a fleck of a few microns (millionths of an inch), which can then be tested to ensure the lasers are set at the correct level assuring no danger of damage to the painting. (Robertson extracted the sample himself prior to arriving at the conference. He did not allow anyone else to touch his purported Harris before, during, or after the test.)

Here’s how ProSpect* Scientific describes the ‘rehearsal’ test on the paint chip,

Tests on this chip were done simply to ensure we knew what power levels were safe for use on the painting.  While David R stated he believed the painting was oil on canvas without lacquer, we were not entirely certain of that.  Lacquer tends to be easier to burn than oil pigments and so we wanted to work with this chip just to be entirely certain there was no risk to the painting itself.

The preliminary (rehearsal) test resulted in a line graph that showed the frequencies of the various pigments in the test sample. Titanium dioxide, for example, was detected and its frequency (spectra) reflected on the graph.

I found this example of a line graph representing the spectra (fingerprint) for a molecule of an ultramarine (blue) pigment along with a general explanation of a Raman ‘fingerprint’. There is no indication as to where the ultramarine pigment was obtained. From the  WebExhibits.org website featuring a section on Pigments through the Ages and a webpage on Spectroscopy,

raman-ArtPigment

Ultramarine [downloaded from http://www.webexhibits.org/pigments/intro/spectroscopy.html]

Raman spectra consist of sharp bands whose position and height are characteristic of the specific molecule in the sample. Each line of the spectrum corresponds to a specific vibrational mode of the chemical bonds in the molecule. Since each type of molecule has its own Raman spectrum, this can be used to characterize molecular structure and identify chemical compounds.

Most people don’t realize that the chemical signature (spectra) for pigment can change over time with new pigments being introduced. Finding a pigment that was on the market from 1970 onwards in a painting by Jackson Pollock who died in 1956 suggests strongly that the painting couldn’t have come from Pollock’s hand. (See Michael Shnayerson’s May 2012 article, A Question of Provenance, in Vanity Fair for more about the Pollock painting. The article details the fall of a fabled New York art gallery that had been in business prior to the US Civil War.)

The ability to identify a pigment’s molecular fingerprint means that an examination by Raman spectroscopy can be part of an authentication, a restoration, or a conservation process. Here is how a representative from ProSpect Scientific describes the process,

Raman spectroscopy is non-destructive (when conducted at the proper power levels) and identifies the molecular components in the pigments, allowing characterization of the pigments for proper restoration or validation by comparison with other pigments of the same place/time. It is valuable to art institutions and conservators because it can do this.  In most cases of authentication Raman spectroscopy is one of many tools used and not the first in line. A painting would be first viewed by art experts for technique, format etc, then most often analysed with IR or X-Ray, then perhaps Raman spectroscopy. It is impossible to use Raman spectroscopy to prove authenticity as paint pigments are usually not unique to any particular painter.  Most often Raman spectroscopy is used by conservators to determine proper pigments for appropriate restoration.  Sometimes Raman will tell us that the pigment isn’t from the time/era the painting is purported to be from (anachronisms).

Autumn Harbour test

Getting back to the June 3, 2014 tests, once the levels were set then it was time to examine Autumn Harbour itself to determine the spectra for the various pigments.  ProSpect Scientific has provided an explanation of the process,

This spectrometer was equipped with an extension that allowed delivery of the laser and collection of the scattered light at a point other than directly under the microscope. We could also have used a flexible fibre optic probe for this, but this device is slightly more efficient. This allowed us to position the delivery/collection point for the light just above the painting at the spot we wished to test. For this test, we don’t sweep across the surface, we test a small pinpoint that we feel is a pigment of the target colour.

We only use one laser at a time. The system is built so we can easily select one laser or another, depending on what we wish to look at. Some researchers have 3 or 4 lasers in their system because different lasers provide a better/worse raman spectrum depending on the nature of the sample. In this case we principally used the 785nm laser as it is better for samples that exhibit fluorescence at visible wavelengths. 532nm is a visible wavelength.  For samples that didn’t produce good signal we tried the 532nm laser as it produces better signal to noise than 785nm, generally speaking. I believe the usable results in our case were obtained with the 785nm laser.

The graphed Raman spectra shows peaks for the frequency of scattered light that we collect from the laser-illuminated sample (when shining a laser on a sample the vast majority of light is scattered in the same frequency of the laser, but a very small amount is scattered at different frequencies unique to the molecules in the sample). Those frequencies correspond to and identify molecules in the sample. We use a database (on the computer attached to the spectrometer) to pattern match the spectra to identify the constituents.

One would have thought ‘game over’ at this point. According to some informal sources, Canada has a very small (almost nonexistent) data bank of information about pigments used in its important paintings. For example, the federal government’s Canadian Conservation Institute (CCI) has a very small database of pigments and nothing from Lawren Harris paintings [See the CCI’s response in this addendum], so the chances that David Robertson would have been able to find a record of pigments used by Lawren Harris roughly in the same time period that Autumn Harbour seems to have been painted are not good.

Everything changes

In a stunning turn of events and despite the lack of enthusiasm from Vancouver Art Gallery (VAG) curator, Ian Thom, on Wednesday, June 4, 2014 the owner of the authenticated Harris, Hurdy Gurdy, relented and brought the painting in for tests.

Here’s what the folks from ProSpect Scientific had to say about the comparison,

Many pigments were evaluated. Good spectra were obtained for blue and white. The blue pigment matched on both paintings, the white didn’t match. We didn’t get useful Raman spectra from other pigments. We had limited time, with more time we might fine tune and get more data.

One might be tempted to say that the results were 50/50 with one matching and the other not, The response from the representative of ProSpect Scientific is more measured,

We noted that the mineral used in the pigment was the same.  Beyond that is interpretation:  Richard offered the view that lapis-lazuli was a typical and characteristic component for blue in that time period (early 1900’s).   We saw different molecules in the whites used in the two paintings, and Richard offered that both were characteristic of the early 1900’s.

Part 1

Part 3

Part 4

* ‘ProsPect’ changed to ‘ProSpect’ on June 30, 2014.

ETA July 14, 2014 at 1300 hours PDT: There is now an addendum to this series, which features a reply from the Canadian Conservation Institute to a query about art pigments used by Canadian artists and access to a database of information about them.

Lawren Harris (Group of Seven), art authentication, and the Canadian Conservation Insitute (addendum to four-part series)

 

Art (Lawren Harris and the Group of Seven), science (Raman spectroscopic examinations), and other collisions at the 2014 Canadian Chemistry Conference (part 1 of 4)

One wouldn’t expect the 97th Canadian Chemistry Conference held in Vancouver, Canada from  June 1 – 5, 2014 to be an emotional rollercoaster. One would be wrong. Chemists and members of the art scene are not only different from thee and me, they are different from each other.

Setting the scene

It started with a May 30, 2014 Simon Fraser University (SFU) news release,

During the conference, ProSpect Scientific has arranged for an examination of two Canadian oil paintings; one is an original Lawren Harris (Group of Seven) titled “Hurdy Gurdy” while the other is a painting called “Autumn Harbour” that bears many of Harris’s painting techniques. It was found in Bala, Ontario, an area that was known to have been frequented by Harris.

Using Raman Spectroscopy equipment manufactured by Renishaw (Canada), Dr. Richard Bormett will determine whether the paint from both works of art was painted from the same tube of paint.

As it turns out, the news release got it somewhat wrong. Raman spectroscopy testing does not make it possible to* determine whether the paints came from the same tube, the same batch, or even the same brand. Nonetheless, it is an important tool for art authentication, restoration and/or conservation and both paintings were scheduled for testing on Tuesday, June 3, 2014. But that was not to be.

The owner of the authenticated Harris (Hurdy Gurdy) rescinded permission. No one was sure why but the publication of a June 2, 2014 article by Nick Wells for Metro News Vancouver probably didn’t help in a situation that was already somewhat fraught. The print version of the Wells article titled, “A fraud or a find?” showed only one painting “Hurdy Gurdy” and for anyone reading quickly, it might have seemed that the Hurdy Gurdy painting was the one that could be “a fraud or a find.”

The dramatically titled article no longer seems to be online but there is one (also bylined by Nick Wells) dated June 1, 2014 titled, Chemists in Vancouver to use lasers to verify Group of Seven painting. It features (assuming it is still available online) images of both paintings, the purported Harris (Autumn Harbour) and the authenticated Harris (Hurdy Gurdy),

"Autumn Harbour" [downloaded from http://metronews.ca/news/vancouver/1051693/chemists-in-vancouver-to-use-lasers-to-verify-group-of-seven-painting/]

“Autumn Harbour” [downloaded from http://metronews.ca/news/vancouver/1051693/chemists-in-vancouver-to-use-lasers-to-verify-group-of-seven-painting/]

Heffel Fine Art Auction

Lawren Harris’‚ Hurdy Gurdy, a depiction of Toronto’s Ward district is shown in this handout image. [downloaded from http://metronews.ca/news/vancouver/1051693/chemists-in-vancouver-to-use-lasers-to-verify-group-of-seven-painting/]

David Robertson who owns the purported Harris (Autumn Harbour) and is an outsider vis à vis the Canadian art world, has been trying to convince people for years that the painting he found in Bala, Ontario is a “Lawren Harris” painting. For anyone unfamiliar with the “Group of Seven” of which Lawren Harris was a founding member, this group is legendary to many Canadians and is the single most recognized name in Canadian art history (although some might argue that status for Emily Carr and/or Tom Thomson; both of whom have been, on occasion, honorarily included in the Group).  Robertson’s incentive to prove “Autumn Harbour” is a Harris could be described as monetary and/or prestige-oriented and/or a desire to make history.

The owner of the authenticated Harris “Hurdy Gurdy” could also be described as an outsider of sorts [unconfirmed at the time of publication; a June 26, 2014 query is outstanding], gaining entry to that select group of people who own a ‘Group of Seven’ painting at a record-setting price in 2012 with the purchase of a piece that has a provenance as close to unimpeachable as you can get. From a Nov. 22, 2012 news item on CBC (Canadian Broadcasting Corporation) news online,

Hurdy Gurdy, one of the finest urban landscapes ever painted by Lawren Harris, sold for $1,082,250, a price that includes a 17 per cent buyer’s premium. The pre-sale estimate suggested it could go for $400,000 to $600,000 including the premium.

The Group of Seven founder kept the impressionistic painting of a former Toronto district known as the Ward in his own collection before bequeathing it to his daughter. It has remained in the family ever since.

Occasionally, Harris “would come and say, ‘I need to borrow this back for an exhibition,’ and sometimes she wouldn’t see [the paintings] again,” Heffel vice-president Robert Heffel said. “Harris asked to have this painting back for a show…and she said ‘No, dad. Not this one.’ It was a painting that was very, very dear to her.”

It had been a coup to get access to an authenticated Harris for comparison testing so Hurdy Gurdy’s absence was a major disappointment. Nonetheless, Robertson went through with the scheduled June 3, 2014 testing of his ‘Autumn Harbour’.

Chemistry, spectroscopy, the Raman system, and the experts

Primarily focused on a technical process, the chemists (from ProSpect* Scientific and Renishaw) were unprepared for the drama and excitement that anyone associated with the Canadian art scene might have predicted.  From the chemists’ perspective, it was an opportunity to examine a fabled piece of Canadian art (Hurdy Gurdy) and, possibly, play a minor role in making Canadian art history.

The technique the chemists used to examine the purported Harris, Autumn Harbour, is called Raman spectroscopy and its beginnings as a practical technique date back to the 1920s. (You can get more details about Raman spectroscopy in this Wikiipedia entry then will be given here after the spectroscopy description.)

Spectroscopy (borrowing heavily from this Wikipedia entry) is the process where one studies the interaction between matter and radiated energy and which can be measured as frequencies and/or wavelengths. Raman spectroscopy systems can be used to examine radiated energy with low frequency emissions as per this description in the Raman spectroscopy Wikipedia entry,

Raman spectroscopy (/ˈrɑːmən/; named after Sir C. V. Raman) is a spectroscopic technique used to observe vibrational, rotational, and other low-frequency modes in a system.[1] It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down.

The reason for using Raman spectroscopy for art authentication, conservation, and/or restoration purposes is that the technique, as noted earlier, can specify the specific chemical composition of the pigments used to create the painting. It is a technique used in many fields as a representative from ProSpect Scientific notes,

Raman spectroscopy is a vital tool for minerologists, forensic investigators, surface science development, nanotechnology research, pharmaceutical research and other applications.  Most graduate level university labs have this technology today, as do many government and industry researchers.  Raman spectroscopy is now increasingly available in single purpose hand held units that can identify the presence of a small number of target substances with ease-of-use appropriate for field work by law enforcers, first responders or researchers in the field.

About the chemists and ProSpect Scientific and Renishaw

There were two technical experts attending the June 3, 2014 test for the purported Harris painting, Autumn Harbour, Dr. Richard Bormett of Renishaw and Dr. Kelly Akers of ProSpect Scientific.

Dr. Kelly Akers founded ProSpect Scientific in 1996. Her company represents Renishaw Raman spectroscopy systems for the most part although other products are also represented throughout North America. Akers’ company is located in Orangeville, Ontario. Renishaw, a company based in the UK. offers a wide line of products including Raman spectroscopes. (There is a Renishaw Canada Ltd., headquartered in Mississauga, Ontario, representing products other than Raman spectroscopes.)

ProSpect Scientific runs Raman spectroscopy workshops, at the Canadian Chemistry Conferences as a regular occurrence, often in conjunction with Renishaw’s Bormett,. David Robertson, on learning the company would be at the 2014 Canadian Chemistry Conference in Vancouver, contacted Akers and arranged to have his purported Harris and Hurdy Gurdy, the authenticated Harris, tested at the conference.

Bormett, based in Chicago, Illinois, is Renishaw’s business manager for the Spectroscopy Products Division in North America (Canada, US, & Mexico).  His expertise as a spectroscopist has led him to work with many customers throughout the Americas and, as such, has worked with several art institutions and museums on important and valuable artifacts.  He has wide empirical knowledge of Raman spectra for many things, including pigments, but does not claim expertise in art or art authentication. You can hear him speak at a 2013 US Library of Congress panel discussion titled, “Advances in Raman Spectroscopy for Analysis of Cultural Heritage Materials,” part of the Library of Congress’s Topics in Preservation Series (TOPS), here on the Library of Congress website or here on YouTube. The discussion runs some 130 minutes.

Bormett has a PhD in analytical chemistry from the University of Pittsburgh. Akers has a PhD in physical chemistry from the University of Toronto and is well known in the Raman spectroscopy field having published in many refereed journals including “Science” and the “Journal of Physical Chemistry.”  She expanded her knowledge of industrial applications of Raman spectroscopy substantive post doctoral work in Devon, Alberta at the CANMET Laboratory (Natural Resources Canada).

About Renishaw InVia Reflex Raman Spectrometers

The Raman spectroscopy system used for the examination, a Renishaw InVia Reflex Raman Spectrometer, had

  • two lasers (using 785nm [nanometres] and 532nm lasers for this application),
  • two cameras,
    (ProSpect Scientific provided this description of the cameras: The system has one CCD [Charged Coupled Device] camera that collects the scattered laser light to produce Raman spectra [very sensitive and expensive]. The system also has a viewing camera mounted on the microscope to allow the user to visually see what the target spot on the sample looks like. This camera shows on the computer what is visible through the eyepieces of the microscope.)
  • a microscope,
  • and a computer with a screen,

all of which fit on a tabletop, albeit a rather large one.

For anyone unfamiliar with the term CCD (charged coupled device), it is a sensor used in cameras to capture light and convert it to digital data for capture by the camera. (You can find out more here at TechTerms.com on the CCD webpage.)

Part 2

Part 3

Part 4

* ‘to’ added to sentence on June 27, 2014 at 1340 hours (PDT). ‘ProsPect’ corrected to ‘ProSpect’ on June 30, 2014.

ETA July 14, 2014 at 1300 hours PDT: There is now an addendum to this series, which features a reply from the Canadian Conservation Institute to a query about art pigments used by Canadian artists and access to a database of information about them.

Lawren Harris (Group of Seven), art authentication, and the Canadian Conservation Insitute (addendum to four-part series)

Sensitive plasmon resonance and the Lycurgus Cup

It’s been a while since I’ve written about the Lycurgus Cup (my Sept. 21, 2010 posting). Dated from the 4th Century AD or CE, the cup is often cited as ancient nanotechnology due to certain optical properties made possible by the inclusion of nanoparticles so it glows green or red depending on the direction of the light.

A Feb. 14, 2013 news item on ScienceDaily features some work in the area of nanoplasmonics that was inspired by the cup,

Utilizing optical characteristics first demonstrated by the ancient Romans, researchers at the University of Illinois at Urbana-Champaign have created a novel, ultra-sensitive tool for chemical, DNA, and protein analysis.

“With this device, the nanoplasmonic spectroscopy sensing, for the first time, becomes colorimetric sensing, requiring only naked eyes or ordinary visible color photography,” explained Logan Liu, an assistant professor of electrical and computer engineering and of bioengineering at Illinois. “It can be used for chemical imaging, biomolecular imaging, and integration to portable microfluidics devices for lab-on-chip-applications. His research team’s results were featured in the cover article of the inaugural edition of Advanced Optical Materials (AOM, optical section of Advanced Materials).

The Lycurgus cup was created by the Romans in 400 A.D. Made of a dichroic glass, the famous cup exhibits different colors depending on whether or not light is passing through it; red when lit from behind and green when lit from in front. It is also the origin of inspiration for all contemporary nanoplasmonics research — the study of optical phenomena in the nanoscale vicinity of metal surfaces.

The University of Illinois College of Engineering Feb. 14, 2013 news release, which originated the news item,

“This dichroic effect was achieved by including tiny proportions of minutely ground gold and silver dust in the glass,” Liu added. “In our research, we have created a large-area high density array of a nanoscale Lycurgus cup using a transparent plastic substrate to achieve colorimetric sensing. The sensor consists of about one billion nano cups in an array with sub-wavelength opening and decorated with metal nanoparticles on side walls, having similar shape and properties as the Lycurgus cups displayed in a British museum. Liu and his team were particularly excited by the extraordinary characteristics of the material, yielding  100 times better sensitivity than any other reported nanoplasmonic device.

This image shows a model of nano cup arrays. (Credit: University of Illinois at Urbana-Champaign)

This image shows a model of nano cup arrays. (Credit: University of Illinois at Urbana-Champaign)

Here’s a little more about colorimetrics and what the researchers are trying to accomplish (from the news release; Note: A link has been removed),

Colorimetric techniques are mainly attractive because of their low cost, use of inexpensive equipment, requirement of fewer signal transduction hardware, and above all, providing simple-to-understand results. … The current design will also enable new technology development in the field of DNA/protein microarray.

“Our label-free colorimetric sensor eliminates the need of problematic fluorescence tagging of DNA/ protein molecules, and the hybridization of probe and target molecule is detected from the color change of the sensor,” stated Manas Gartia, first author of the article, “Colorimetrics: Colorimetric Plasmon Resonance Imaging Using Nano Lycurgus Cup Arrays.” “Our current sensor requires just a light source and a camera to complete the DNA sensing process. This opens the possibility for developing affordable, simple and sensitive mobile phone-based DNA microarray detector in near future. Due to its low cost, simplicity in design, and high sensitivity, we envisage the extensive use of the device for DNA microarrays, therapeutic antibody screening for drug discovery, and pathogen detection in resource poor setting.”

In addition to Gartia and Liu, the paper’s co-authors included Austin Hsiao, Anusha Pokhriyal, Sujin Seo, Gulsim Kulsharova, and Brian T. Cunningham at Illinois, and  Tiziana C. Bond, at the Meso, Micro and Nano Technologies Center at Lawrence Livermore National Laboratory, California.

The team’s article is behind a paywall and you can find a complete citation by clicking on the link to ScienceDaily news item.

All about the University of Calgary and its microscopy and imaging facility

A July 24, 2012 news item on Nanowerk features the the equipment and capabilities of …

The Calgary Microscopy and Imaging Facility (MIF) is a world-class university-wide facility housing transmission electron microscopy (TEM), scanning electron microscopy (SEM), advanced light microscopy, atomic force microscopy (AFM), including single cell force spectroscopy (SCFS), and advanced image processing for three-dimensional electron and light microscopy, directed by Professor Matthias Amrein.

Single cell force spectroscopy at the MIF has now attracted high profile research with three NanoWizard® AFM systems from JPK [Instruments], one of which is equipped with the CellHesion® module. Describing the work of the Calgary group, Professor Amrein says “While we do some work for the energy sector (to predict behaviour of nanoparticles injected into oil reservoirs) our main focus is medicine. We delve into very fundamental problems such as “how does a malaria red blood cell attach itself to a blood vessel” or “how does binding of a ligand to a cell surface receptor or contact of a crystalline surface with the plasma membrane drive lipid sorting and how will this lead to signalling” but then immediately apply it to a practical problem such as “how does contact of uric acid crystals with dendritic cells cause gout in affected joints and how can we prevent this occurrence?” We want to understand disease processes at a very fundamental level so we know how to intervene in the best possible way. For example, a chronic inflammatory disease such as gout or arteriosclerosis may be triggered by a very specific interaction of a particle (uric acid crystals, cholesterol crystals, amyloid plaque, …. ) and specific cell (dendritic cell, macrophage, T-cell, …). Understanding this interaction will lead to targeted treatment “block the interaction” rather than the non-specific dampening of inflammation such as by corticosteroids with its many well-documented side effects and limited efficacy.”

It’s always nice to get some information about activities in microscopy, etc. in Canada although I’m not sure what occasioned the news item/release.