From nanowerk news:

Nanoparticles — those with diameters less than one-thousandth the width of a human hair — are increasingly prevalent in high technology, medicine, and consumer goods. Their characteristics, both desirable and undesirable, depend critically on their size.

For example, a nanoparticle (NP) in the bloodstream that is 50 nanometers (nm, billionths of a meter) wide may have limited effect on the cells it encounters; but a 20 nm version of exactly the same material can be toxic. Size considerations are especially important if, as anticipated, NPs come to play a major role in cancer therapy.  As a result, accurate measurements of a particle’s volume are essential.

But the volume measured using different tools can vary substantially. For example, a new analysis by scientists at NIST (Analytical and Bioanalytical Chemistry, “Volume determination of irregularly-shaped quasi-spherical nanoparticles”) has shown that when the same set of NPs is measured with the two most widely used reference methods, calculated volume estimates can differ by as much as 160% owing to inherent biases in each method. To rectify that situation, the researchers have proposed and tested a novel combined measurement scheme that can minimize errors while still maintaining high measurement throughput.

“For a long time, even though many people were working on this problem, there have been different answers from the different methods and nobody seemed to know what method was correct or what is the correct size of nanoparticles,” says Ravikiran Attota, who headed the research.

 

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Image Credit:     NIH

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