Hg detection and information encryption of new [1+1] lanthanide cluster.

The sensing of heavy metal ion and information encryption are two very important research areas. Therefore, developing multi-functional materials capable of sensing heavy metal ions and encrypting information is highly important. In this work, three [1 + 1] lanthanide clusters [Ln(TFBA)(dmp) (HO)] (Ln = TbTb, EuEu, GdGd, HTFBA = 2,3,4,5-tetrafluorobenzoic acid, dmp = 4,7-dimethyl-1,10-phenanthroline) were designed and synthesized. Among them, Tb shows excellent luminescence sensing towards Hg (Ex = 350 nm, Em = 545 nm). Results demonstrates the sensing with high selectivity, strong anti-interference, 20-s response time, high accuracy, excellent linear relationship in 0-20.0 μM, and a very low limit of detection (0.02 ppb). Furthermore, paper strips based on Tb is fabricated for visual detection of Hg in real samples of tap water, lake water, human urine, and human serum. More interestingly, a new method for confidentiality of information is realized through multi-color anti-counterfeiting patterns with the [1 + 1] lanthanide cluster ink, based on the luminescence "on-off" sensing towards Hg.