A new thiacalix[4]arene-based metal-organic framework as an efficient electrochemical sensor for trace detection of Cd and Pb.

Heavy metal ions (HMIs) can lead to serious harm to human health and ecological environment. Thus, developing an efficient detection method for HMIs is extremely necessary. Herein, a new thiacalix[4]arene-based metal-organic framework (MOF) [Co(L1)(TPA)]·DMA·3CHOH·HO (Co-LTPA) (L1 = thiacalix[4]arene-based ligand and HTPA = terephthalic acid) was successfully synthesized. The electrochemical detection platform (Co-LTPA/GCE) was acquired, and Co-LTPA/GCE featured ultrasensitive detection of HMIs with greatly low limits of detection (LODs) of 0.119 nM for Cd and 0.279 nM for Pb as well as wide linear ranges of 0.08-5.8 μM for Cd and 0.01-6.0 μM for Pb. More importantly, the Co-LTPA/GCE sensor was employed to detect foods (milk, honey and orange juice) and water samples (tap water, lake water and drinking water) with satisfactory recoveries, proving the sensor reliability in practical applications. This work provided an example that the functional electrochemical Co-LTPA/GCE sensor was employed for Cd and Pb detection.