A ratiometric and colorimetric fluorescent probe for the detection of mercury ion based on rhodamine and quinoline-benzothiazole conjugated dyad

Although fluorescent probes had become powerful tools to detect and image mercury ion (Hg2+), most of them suffered from a single signal change. Therefore, a new ratiometric fluorescent probe 1, with a quinoline-benzothiazole group as donor and a rhodamine as acceptor, was constructed for Hg2+ detection in this paper study. Results showed that Probe 1 was highly sensitive and selective to Hg2+, with a linear range of 0-26 mu M and a detection limit (LOD) of 0.2 mu M. Moreover, with excess competitive metal ions in DMF-H2O (v/v, 7/3), probe 1 exhibited excellent colorimetric selectivity and sensitivity to Hg2+ with the significant color change from colorless to pink with a linear range 0-28 mu M and a LOD of 0.37 mu M, because Hg2+ promoted the rhodamine hydrazide opening. And probe 1 finally was used to detect Hg2+ in living cells.