Scheme 1.

“Two birds with one stone” Ru(II) complex responsive probe for biotihols detection and discrimination. A) Schematic representation of the strategy for the detection of total biothiols (“bird” one) and discrimination of GSH and Cys/Hcy (“bird” two) using Ru‐NBD probe (“stone”). B) Schematic illustration of the molecular structure of Ru‐NBD probe and the response mechanism of Ru‐NBD to GSH and Cys/Hcy. C) Molecular orbitals (MOs) of Ru‐NBD and Ru‐OH based on emission transitions theoretical computation.