Two stable cadmium(II) coordination polymers for fluorimetric detection of tetracycline and Fe3+ ions

Abstract

Two stable Cd(II) coordination polymers [Cd(L)(chdc)·(H2O)]n (1) and [Cd(L)(SA)]n (2) (L ​= ​1,6-bis(benzimidazol-1-yl)hexane, H2chdc ​= ​cis-1,2-cyclohexanedicarboxylic acid, H2SA ​= ​suberic acid), were successfully constructed under hydrothermal condition. 1 shows that the 2D structure can be defined as a 63-hcb layer. 2 displays a rare mog topological framework with the point symbol {4·64·8}2{42·62·82}. 1 and 2 exhibit the high sensing capability through luminescence quenching effects. The limits of detection (LOD) of 1 and 2 for Fe3+ are 8.8 × 10−7 ​mol·L−1 and 1.2 × 10−6 ​mol·L−1, respectively. The LOD toward tetracycline (TC) for 1 is 7.6 × 10−8 ​mol·L−1, for 2 is 3.3 × 10−8 ​mol·L−1. 1 and 2 are firstly promising dual-functional fluorescent sensors based MOFs for detection of Fe3+ and TC with high sensitivity and selectivity. In addition, 1 and 2 exhibit excellent thermal and chemical stability.