Issue



They’re all different


03/01/2006







Engineered nanoparticles appear in a variety of shapes, and their size, shape and composition affect how they behave. Buckyballs, carbon nanotubes, quantum dots, dendrimers and nanoshells are all nanoparticles, but they look and function quite differently.

Each has special properties that make them attractive for specific applications. Quantum dots, for instance, emit light in various colors. Their fluorescent properties can be used as cancer cell markers. Carbon nanotubes can conduct electricity and be semiconductors, making them attractive materials for electronics. Dendrimers can serve as drug delivery devices by ferrying medicine in their branch-like structures.

But often nanoparticles need to be “dressed up” in order to be useful. Nanotubes, for instance need to have molecules attached to keep them from sticking together or to get them to disperse evenly. Dendrimers, quantum dots and nanoshells won’t latch onto cells unless they have antibodies or other biological molecules attached to them.

Adding a molecule onto or into a nanoparticle changes its properties. Nanoparticles whose charged surface makes them toxic, for instance, may become benign once a molecule is wrapped around them. Alternatively, contaminants or other matter may stick onto some nanoparticles, turning them into potentially harmful materials.

Research by Candace Stuart
Illustration by Mike Reeder

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