Rust composite could make gold nanoparticles less pricey

Gold-rust composites as used to replace standard gold nanoparticles. --Courtesy of the University of Georgia

Gold nanoparticles have many uses in drug delivery and diagnostics, but a precious metal even at the nanoscale can cost a lot to manufacture and scale up for use in research and, ultimately, biomedicine. Researchers have found, though, that a type of rust particle could have the properties needed and come at a much lower price.

Scientists at the University of Georgia, in what is dubbed a sort of “modern-day alchemy” (but only on a surface level), have combined gold nanoparticles with magnetic rust particles, resulting in a hybrid structure with properties of both, according to a release.

In making gold nanoparticles from gold ions, when rust was present, the gold would grow on the rust, using it as a sort of support structure. Thus, the scientists ended up with nanoscale gold, and with much less of the metal than would normally be needed to start.

And the properties remained the same. One of the characteristics of gold nanoparticles used most in drug delivery is its retention of light, which it can convert to heat. Introducing gold and other cancer drugs to a tumor, for instance, can allow the release of the drug to target the cancer cells.

“When researchers are looking at gold as a potential material for research, we talk about how expensive gold is,” lead researcher Simona Murph said. “For the first time ever, we've been able to create a new class of cheaper, highly efficient, nontoxic, magnetically reusable hybrid nanomaterials that contain a far more abundant material-rust-than the typical noble metal gold.”