Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dynamic duo to fight crime and cancer

27.10.2014

Miniature two-color barcodes have the potential to combat forgery and track cancerous cells

Tiny rod-like single crystals that act as miniature dual-color barcodes have been synthesized by A*STAR researchers and co-workers. The researchers have demonstrated the potential of these barcodes for two very different applications: anti-counterfeiting measures and cell tracking.


Green NaYF4 microrods with red tips, which are promising for security ink and cell tracking applications.

Reproduced, with permission, from Ref. 1 © 2014 American Chemical Society

So-called lanthanide-doped upconversion materials are highly promising for applications against crime and cancer as they have adjustable morphologies and tunable output wavelengths — they can also be fabricated by inexpensive processes that are easily scaled up.

To date, single-crystal nanocrystals made from these materials have been impractical as multicolor barcodes because their tiny size makes them too small to be observed using conventional optical microscopes.

Xiaogang Liu at the A*STAR Institute of Materials Research and Engineering and co-workers based in Singapore, China and Australia overcame this problem by synthesizing different-colored microscale rods that have red, green or blue tips. These rods are made of a lanthanide-doped upconversion material, NaYF4, and are sufficiently long that their colored tips can be readily resolved using a standard microscope1.

As a first step, the researchers controlled the lengths of the NaYF4 microrods by varying the doping concentration of gadolinium. They then adjusted the color of the microrods by varying the doping concentrations of ytterbium (Yb3+) and erbium (Er3+) ions.

The colored tips were simply a different phase of the same material as the microrods and were fabricated using a minor variation of the same procedure. Different combinations of microrod and tip colors were made by adjusting the doping concentrations of the microrods and tips.

Liu and team demonstrated the potential of these miniature barcodes for anti-forgery measures by producing two transparent security inks: one that contained dual-color microrods with green centers and red tips and a control ink that contained green microrods.

When illuminated by an infrared laser beam and viewed by conventional microscope, printed patterns produced using the two inks are essentially indistinguishable under low magnification and have practically identical spectral properties. However, when observed under high magnification, the red tips of the microrods in the non-control ink are clearly visible, allowing the two inks to be easily distinguished from each other.

The researchers also point out that since the microrods can be internalized by cancer cells, it should be possible to use them as optical probes for imaging tumors. Liu notes that unlike conventional ‘top-down’ techniques, which have low yields and are expensive, the use of NaYF4 microrods with tips separated by spacers has the potential to “provide a ‘bottom-up’ solution for gram-scale production of microsized barcodes.”

Reference
(1) Zhang, Y., Zhang, L., Deng, R., Tian, J., Zong, Y. et al. Multicolor barcoding in a single upconversion crystal. Journal of the American Chemical Society 136, 4893–4896 (2014). 

Associated links

A*STAR Research | Research SEA News
Further information:
http://www.research.a-star.edu.sg
http://www.researchsea.com

More articles from Health and Medicine:

nachricht Potential seen for tailoring treatment for acute myeloid leukemia
10.12.2018 | University of Washington Health Sciences/UW Medicine

nachricht UC San Diego researchers develop sensors to detect and measure cancer's ability to spread
06.12.2018 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Small but ver­sat­ile; key play­ers in the mar­ine ni­tro­gen cycle can util­ize cy­anate and urea

10.12.2018 | Life Sciences

New method gives microscope a boost in resolution

10.12.2018 | Physics and Astronomy

Carnegie Mellon researchers probe hydrogen bonds using new technique

10.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>