Computer Model Details QD Interaction with Protein

A new computer modeling approach could increase understanding of how nanoscale quantum dots (QDs) interact with biological systems.

QDs are used in a number of bioimaging applications, including in vivo imaging of tumor cells, detection of biomolecules and measurement of pH changes. But proteins tend to surround the nanoparticles, forming a corona that changes their sensitivity to light.

A model of a firefly luciferase protein corona around a CdSe quantum dot. Courtesy of Drs. Shikha Nangia and Arindam Chakraborty/ Syracuse University.

Researchers at Syracuse University said they have addressed a “computational bottleneck” that limited theoretical study of protein coronas. Their method combines pseudopotential and explicitly correlated Hartree-Fock quantum mechanical calculations with classical molecular mechanics and dynamics, as well as Monte Carlo techniques.

The team modeled the formation of a corona around a 5 nm cadmium selenide QD, finding that it produced an 8-nm red shift. They said the technique can be applied to bigger and more complex QD systems.

The research was published in the Journal of Chemical Theory and Computation (doi: 10.1021/ct500681m).

For more information, visit www.syr.edu.