With the growing popularity of gold nanorods, it has become
critical to consider the environmental and overall health impacts
resulting from their synthesis as well as the high cost of gold.
We hypothesized that due to a small gold conversion percentage,
supernatant solutions contained excess reagents needed for additional
rod growth when properly treated. As a result, we proposed
an alternative approach whereby previously discarded supernatant
solutions were used as ‘‘new” growth solutions. These solutions
generated monodisperse gold nanorods through 5 iterations of
supernatant solutions resulting in 75% total gold conversion
making this approach more robust for efficient transformation of
gold into nanorods. While other groups have reported improved
gold conversion efficiency, this is the first report, to the best of
our knowledge, of increased conversion in individual supernatant
solutions allowing for independent aspect ratio control [