CEINT researchers pioneer a microscopy technique that can detect and characterize nanoparticles at biologically relevant concentrations and under conditions that mimic surface and ground water (Environ. Sci. Technol., DOI: 10.1021/es204140s).
Appala Raju Badireddy, Mark Wiesner and
Jie Liu are authors of ES&T's Top Technology Article 2012.
Using a dark field microscope called a CytoViva Hyperspectral Imaging System, postdoctoral researcher Appala Raju Badireddy provided never-before-seen detailed profiles of multiple nanomaterials in laboratory as well as real world conditions. The dark field technique leaves a black background, but the scattered light from silver nanoparticles paint a "multicolor starscape" in the foreground. In the ES&T paper, the researchers first characterized more than a dozen types of engineered nanoparticles, including carbon nanotubes, as well as silver, gold, and titanium dioxide nanoparticles. They then used this library of spectra to examine nanoparticle mixtures in ultrapure water and observed changes in the coatings on silver nanoparticles. The team also mapped the locations of and estimated abundances of silver nanoparticle samples collected from complex simulated wetland systems (mesocosms) and from a wastewater field sample. These tests demonstrated that the technique was sensitive enough to analyze complex environmental samples containing nanomaterials.
Researchers at Duke are using this technique to study the uptake of nanomaterials animal and plant models, and to better control the incorporation of nanomaterials into nanopolymer composites.
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