Gold and silver have long been valued as monetary metals, substances of beauty and ornamentation; secure stores of wealth and even as industrial components. Within the last decade, gold has been increasingly used as a nano-pharmaceutical, capable of penetrating cell walls in order to precisely target delivery of medicines, heat from x-rays used to destroy cancer cells and for cellular imaging. Silver was deemed too unstable for such uses.
But in fall 2013, scientists stumbled upon a silver nanoparticle that promises to be even more stable and easy to use than gold.
Since 2008, gold nanoparticles, sub-microscopic, sphere-shaped particles about one-10,000th the diameter of a single strand of human hair, have been used in medical treatments, unique in their ability penetrate human cell walls without destroying the cells. For a long time, even as they devised new and more sophisticated ways of using gold nanoparticles to target particular types of cells, scientists didn’t really know how or why it worked.