Abstract
The present communication reports on the use of sweet potatoes as carbon source for green synthesis of fluorescent carbon nanodots (CNDs) ranging from 1 to 3 nm. We further demonstrate the use of such CNDs as a very effective fluorescent probe for label-free, sensitive, and selective detection of Hg2+ with a detection limit as low as 1 nM. The feasibility of the CNDs for analysis of Hg2+ in a real water sample is also demonstrated successfully.