Nanocrystal Tags Aid Rapid Pathogen Detection

Tunable nanoparticles could pave the way for screenings that identify thousands of target molecules simultaneously — and even detect multiple viruses within minutes.

A team from Purdue University and Macquarie University used tunable luminescent nanocrystals as tags, applying them to high-speed scanning technology.

The development builds on the team’s previous work, in which they discovered how to control how long nanoparticles (called tau-dots) luminesce via luminescence resonance energy transfer (LRET). The lifespan of the nanoparticle light, measured in milliseconds to microseconds, and its color can make the difference in creating unique tags for biomedical screening, according to the researchers.

The luminescence lifetime identity of each target is decoded in real time. Courtesy of Nature Communications.

“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 Dr. Yiqing Lu, a research fellow at Macquarie who led the work.

The team attached unique tags to DNA strands of HIV, Ebola, hepatitis-B and human papillomavirus-16. Each was read accurately and was distinguishable in suspension arrays at high speeds.

“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,” Lu said.

The researchers will continue their biological testing under the direction of Dr. J. Paul Robinson, a professor of cytomics in Purdue's College of Veterinary Medicine and its Weldon School of Biomedical Engineering. “The next step is to perform such high-throughput testing within a liquid, like water, blood or urine,” he said.

The testing of liquids has the potential for widespread biological use and clinical applications, Robinson added, as well as detection of pathogens in food or water.

The researchers also plan to develop instrumentation that can measure the tags, and how the new technology could benefit more health care and biodetection applications.

The work was funded by the Australian Research Council. It is published in Nature Communications (doi: 10.1038/ncomms4741).

For more information, visit: www.purdue.edu.