Using H 2 O 2 as a green oxidant to produce fluorescent GaOOH nanomaterials from a liquid metal.

We report a simple and rapid method for the synthesis of fluorescent gallium oxyhydroxide (GaOOH) nanoparticles from liquid Ga by a probe sonication method in the presence of H 2 O 2 as an oxidant. The aspect ratio of the GaOOH nanoparticles is determined by the concentration of H 2 O 2 and solution pH, as well as the probe energy and sonication time. Further surface modification with cyclodextrin to achieve biocompatibility for potential biomedical applications is reported where an example of cell uptake and fluorescence imaging is shown.