▎ 摘　　要

Owing to the huge threat to human health and environment from thiosulfate anion (S2O32- ) widely used in various fields, the development of an effective detection method for S2O32- is urgently desired. Herein, we developed an iodine (I2) mediated nitrogen-doped graphene quantum dots (I2-mediated N-GQDs) as a fluorescence ?off-on? probe for S2O32- by iodimetry reaction oriented strategy. Firstly, I2 interacted with N-GQDs to form non-fluorescent N-GQDs/I2 complex due to the inner filter effect (IFE). In the presence of S2O32-, the iodimetry reaction between I2 and S2O32- disintegrated N-GQDs/I2 complex and re-switched on the quenched photoluminscence of N-GQDs. The I2-mediated N-GQDs nanoprobe with a limit of detection down to 93 pM has been successfully used to sense S2O32- in biological fluids and living cells. Moreover, the I2-mediated N-GQDs/S2O32nanoplatform could further detect oxidative compounds such as hydrogen dioxide, dichromate, permanganate, iron ion (III), copper ion (II), and cerium ion (IV).