Terbium-based metal-organic frameworks through energy transfer modulation for visual logical sensing zinc and fluorine ions

Zinc is the second most abundant trace element in the human central nervous system, which is closely related to various physiological activities in the human body. Fluoride ion is one of the most harmful elements in drinking water. Excessive intake of F- may cause dental fluorosis, renal failure, or DNA damage. Therefore, it is urgent to develop sensors with high sensitivity and selectivity for the detection of Zn2+ and F- ions at the same time. In this work, a series of mixed lanthanide metal-organic frameworks (Ln-MOFs) probes are synthesized using a simple method of in situ doping. The luminous color can be finely modulated by changing the molar ratio of Tb3+ and Eu3+ during synthesis. Benefiting from the unique energy transfer modulation mechanism, the probe has the continuous detection capability of zinc ions and fluoride ions. The detection of Zn2+ and F- in a real environment shows that the probe has a good practical application prospect. The as-designed sensor at 262 nm excitation can sequentially detect Zn2+ concentrations ranging from 10-8 to 10-3 M (LOD = 4.2 nM) and F- levels ranging from 10-5 to 10-3 M (LOD = 3.6 μM) with high selectivity. Based on different output signals, a simple Boolean logic gate device is constructed to realize intelligent visualization of Zn2+ and F- monitoring.