Controlled formation of gold nanoflowers by reduction of tetrachloroauric acid with thermally treated glucose in alkaline solution

Herein, thermally treated glucose in alkaline solution at 60 °C for 10 min was used to reduce tetrachloroauric acid for the preparation of gold nanoflowers within the size range of 50–520 nm. The use of the glucose activated for a longer period of time led to the formation of gold nanoparticles with less anisotropic characteristics. The degradation of glucose in alkaline solution results in enediols and carboxylates. It was suggested that the product has stronger reduction ability and limited protection effect for tetrachloroauric acid and gold nanoparticles, respectively, contributes to the controlled formation of gold nanoflowers. The as-prepared gold nanoflowers showed better surface enhanced Raman scattering (SERS) activity than citrate or PVP coated ones when rhodamine 6G (R6G) was used as probe molecule.