Unexpected formation of gold nanoflowers by a green synthesis method as agents for a safe and effective photothermal therapyElectronic supplementary information (ESI) available. See DOI: 10.1039/c7nr06286a

Star fruit ( Averrhoa carambola ) juice rich in vitamin C and polyphenolic antioxidants was used to synthesize branched gold nanoflowers. These biocompatible and stable gold nanoflowers show strong near-infrared absorption. They are successfully demonstrated to be highly efficient for both in vitro and in vivo photothermal therapy by using an 808 nm laser. A green synthesis of gold nanoflowers with photothermal therapeutic potential was achieved by using star fruit juice and gold chloride.