Highly sensitive and selective sensing of CH3Hg+ via oscillation effect in Eu-cluster

A new dinuclear europium cluster (Eu-cluster) is synthesized and the exact structure is determined by single-crystal X-ray diffraction. The formula of the Eu-cluster is determined to be [Eu 2 (4-Msal) 6 (phen) 2 (H 2 O) 2 ] (4-Msal   =   4-methylsalicylic acid, phen   =   phenanthroline), it crystallizes in the triclinic space group P -1, with a   =   9.1193(8)   Å, b   =   13.0855(10)   Å, c   =   14.0981(9)   Å, α   =   103.159(6)°, β   =   94.192(6)°, γ   =   100.632(7)°, V   =   1598.3(2)   Å 3 and Z   =   1. Further investigation reveals that the Eu-cluster is a highly sensitive and selective methylmercury (CH 3 Hg + ) sensor. To the best of our knowledge, this is the first CH 3 Hg + sensor based on lanthanide clusters/complexes. The responsive behavior shows the sensing has excellent linearity in 1.4–3.8   μg   L −1   μM. The LOD for sensing CH 3 Hg + is 0.8   μg   L −1 , which meets the standard of Chinese environmental quality standard for agricultural and industrial water. Interestingly, study also reveals the sensor is applicable in real water sensing.