Using a Nanostar as a Tracer, Label or Contrast Agent

A study by bioengineers at Duke University (Durham, North Carolina, USA) indicates that amongst the different shapes of nanoparticles, stars may be the best for certain applications.

The essential factor is how light reflects off the particles. Compared with rods, cubes, cones and spheres, nanostars can significantly enhance the reflected light, which increases their potential usefulness as a tracer, label or contrast agent, says a report at www.physorg.com

A paper has been published online in the Journal of Physical Chemistry. Its lead author, Chris Khoury, believes that this is the first report on the use of gold nanostars as labels for molecular detection and their controlled synthesis.

Khoury “grew” the nanostars by mixing miniscule gold particle seeds in a growth solution. As more gold was added to the solution, protrusions began to sprout from the central core. Additional gold increased the size of the entire particle.

“These experiments demonstrate that it is possible to vary the size and shape of the nanostars in a controlled fashion by adjusting the volume of gold seeds added to the growth solution,” he said. “We found that variations in star size changed the reflected light, which hints toward the tuning capabilities that can be exploited by surface-enhanced Raman scattering technology.”

The nanostars are small enough to pass through cell walls into the interior of the cell, which would make them an effective method for molecular diagnostics. Nanostars could be attached to an antibody to search for antigens or coupled with a dye to improve the effectiveness of different imaging tests.

Tags: Diagnostics, Duke University, nanoparticles, Nanostar, Nanotechnology and Microtechnology