The work, published in the Proceedings of the National Academy of Sciences, reported on the use of two-photon luminescence (TPL) imaging of single gold nanorods used to track blood flowing through a mouse's ear. This method improves on the previous method of TPL which used a signal from a rhodamine molecule. The new signal from the gold nanorods is 58 times brighter than the previous method,and also has the advantage of having tunable absorption properties in the near-infrared, plus being biologically inert.

Using gold nanorods will hopefully allow earlier detection of diseases such as cancer.