Wednesday, October 15, 2014

On-the-fly decoding luminescence lifetimes in the microsecond region for lanthanide-encoded suspension arrays

WEST LAFAYETTE, Ind. — A research team using tunable luminescent nanocrystals as tags to advance medical and security imaging have successfully applied them to high-speed scanning technology and detected multiple viruses within minutes.

The research, led by Macquarie University in Sydney, Australia and Purdue University, builds on the team's earlier success in developing a way to control the length of time light from a luminescent nanocrystal lingers, which introduced the dimension of time in addition to color and brightness in optical detection technology.

Detection based on the lifetime of the light from a nanocrystal as well as its specific color exponentially increases the possible combinations and unique tags that could be created for biomedical screens.

"We now are able to build a huge library of lifetime color-coded microspheres to perform multiple medical tasks or diagnoses at the same time," said Yiqing Lu, a researcher at Macquarie University, who led the research. "The time saved by omitting the need to grow or amplify a culture sample for testing and eliminating the need to run multiple tests will save future patients precious time so treatment can begin, which can be life-saving when managing aggressive diseases."

Ebola virus

Ebola virus virion. Created by CDC microbiologist Cynthia Goldsmith, this colorized transmission electron micrograph (TEM) revealed some of the ultrastructural morphology displayed by an Ebola virus virion.

This media comes from the Centers for Disease Control and Prevention's Public Health Image Library (PHIL), with identification number #10816

The technology could enable screens that identify thousands of different target molecules simultaneously, said J. Paul Robinson, the Professor of Cytomics in Purdue's College of Veterinary Medicine and professor in Purdue's Weldon School of Biomedical Engineering, who was involved in the research.

"This is the second part of the puzzle," said Robinson, who led the biological testing of the technology. "Now we've successfully measured the lifetimes of these tags on the fly at thousands of samples per second. The next step is to perform such high-throughput testing within a liquid, like water, blood or urine. That will open the door to widespread biological use and clinical applications, as well as the detection of pathogens in food or water."

Robinson's research focuses on flow cytometry, the analysis of cells that are contained in a liquid flowing past a laser beam. In addition to developing instrumentation to measure the tags, he plans to explore the technology's health care and biodetection applications.

The research team attached unique tags to DNA strands of HIV, Ebola virus, Hepatitis B virus and Human Papillomavirus 16. The tags were accurately read and distinguished at high speeds in suspension arrays. The team's work is detailed in a paper that will be published in the next issue of Nature Communications and is currently available online.

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Dayong Jin, an Australian Research Council Future Fellow, and a professor of photonics at Macquarie ARC Centre for nanoscale BioPhotonics (CNBP), led the design and manufacture of the nanoparticles, which the researchers named tau-dots.

In addition to Jin, Lu and Robinson, paper co-authors include Jie Lu, Jiangbo Zhao, Ewa M. Goldys, and James A. Piper of Macquarie; Janet Cusido and Francisco M. Raymo of the University of Miami; Jingli Yuan of Dalian University of Technology in Dalian, China; , Sean Yang and Robert C. Leif of Newport Instruments in San Diego; and Yujing Huo of Tsinghua Univesity in Beijing, China.

Contact: Elizabeth K. Gardner ekgardner@purdue.edu 765-494-2081 Purdue University www.twitter.com/PurdueResearch

On-the-fly decoding luminescence lifetimes in the microsecond region for lanthanide-encoded suspension arrays.

Ebola virus virion. Created by CDC microbiologist Cynthia Goldsmith, this colorized transmission electron micrograph (TEM) revealed some of the ultrastructural morphology displayed by an Ebola virus virion.

More about this image and story at Nanotechnology Today - http://nanotechnologytoday.blogspot.com/2014/10/on-fly-decoding-luminescence-lifetimes.html

Thursday, September 25, 2014

NRL syntheses potassium superoxide (KO2) to rapidly form oxide nanoparticles from simple salt solutions in water

Scientists at the U.S. Naval Research Laboratory (NRL) Materials Science and Technology Division have developed a novel one-step process using, for the first time in these types of syntheses, potassium superoxide (KO2) to rapidly form oxide nanoparticles from simple salt solutions in water.

"Typically, the synthesis of oxide nanoparticles involves the slow reaction of a weak oxidizing agent, such as hydrogen peroxide, with dilute solutions of metal salts or complexes in both aqueous and non-aqueous solvent systems," said Dr. Thomas Sutto, NRL research chemist. "The rapid exothermic reaction of potassium superoxide with the salt solutions results in the formation of insoluble oxide or hydroxide nanoparticulates."

An important advantage of this method is the capability of creating bulk quantities of materials. NRL has demonstrated that large quantities (over 10 grams) of oxide nanoparticles can be prepared in a single step, which is approximately four orders of magnitude higher yield than many other methods. The metal concentrations, usually in the millimolar (mM) amount, need to be low in order to prevent aggregation of the nanoparticles into larger clusters that could significantly limit the amount of material that can be prepared at any one time.

Oxide nanoparticles have been shown to be crucial components in numerous applications to include electronic and magnetic devices, energy storage and generation, and medical applications such as magnetic nanoparticles for use in magnetic resonance imaging (MRI). In all of these applications, particle size is critical to the utility and function of oxide nanoparticles—decreased particles size results in increased surface area, which can significantly improve the performance of the oxide nanoparticle.

potassium superoxide (KO2) nanoparticles

This figure illustrates the ease with which grams of many different types of oxide nanoparticles can be prepared in a single step. The first row of sample vials shows the initial salt solutions of the different elements. The second row shows the product after reaction with potassium superoxide (KO2) and the addition of methanol. The bottom row shows the grams of nanoparticles after being purified by centrifugation.
(Photo: U.S. Naval Research Laboratory)

In order to demonstrate the broad scale applicability of this new method, oxide or hydroxide nanoparticles have been prepared from representative elements from across the periodic table to rapidly produce nanometer sized oxides or hydroxides. In addition to the elements converted to oxide nanoparticles in the above illustration, it has also been shown that oxide nanoparticles can be prepared from second and third row transition metals, and even semi-metals such as tin, bismuth, thallium and lead.

One exciting aspect of this technique is that it can also be used to produce blends of nanoparticles. This has been demonstrated by preparing more complex materials, such as lithium cobalt oxide—a cathode material for lithium batteries; bismuth manganese oxide—a multiferroic material; and a 90 degrees Kelvin (K) superconducting Yttrium barium copper oxide material. As such, this new synthetic route to oxide nanoparticles also shows great promise for a multitude of other catalytic, electrical, magnetic, or electrochemical processes, from novel cathodes to solution preparation of other types of ceramic materials.

About the U.S. Naval Research Laboratory. The U.S. Naval Research Laboratory is the Navy's full-spectrum corporate laboratory, conducting a broadly based multidisciplinary program of scientific research and advanced technological development. The Laboratory, with a total complement of approximately 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif. NRL has served the Navy and the nation for over 90 years and continues to meet the complex technological challenges of today's world. For more information, visit the NRL homepage or join the conversation on Twitter, Facebook, and YouTube.

NRL syntheses potassium superoxide (KO2) to rapidly form oxide nanoparticles from simple salt solutions in water. More about this image and story at Nanotechnology Today - http://nanotechnologytoday.blogspot.com/2014/09/nrl-syntheses-potassium-superoxide-ko2.html

Scientists at the U.S. Naval Research Laboratory (NRL) Materials Science and Technology Division have developed a novel one-step process using, for the first time in these types of syntheses, potassium superoxide (KO2) to rapidly form oxide nanoparticles from simple salt solutions in water.

"Typically, the synthesis of oxide nanoparticles involves the slow reaction of a weak oxidizing agent, such as hydrogen peroxide, with dilute solutions of metal salts or complexes in both aqueous and non-aqueous solvent systems