Cucurbit[8]uril-Mediated Polypseudorotaxane for Enhanced Lanthanide Luminescence Behavior in Water

A novel supramolecular polypseudorotaxane was successfully constructed with pseudo[3]rotaxanes between pyridine-2,6-dicarboxylic acid imidazolium (G1) and cucurbit[8]uril (CB[8]) and the subsequent coordination with lanthanide ions. Significantly, compared with the pyridine-2,6-dicarboxylic acid imidazolium complex G1@Tb³⁺, CB[8]-mediated polypseudorotaxane CB[8]@G1@Tb³⁺ not only displayed enhanced lanthanide luminescence behavior with a 29.1-fold time enhancement (from 45.76 μs to 1.33 ms) of the excited-state lifetime (τ) and a 8.7-fold increase (from 0.89% to 7.81%) in the quantum yield (Φ) but also exhibited a specific fluorescence response to antibiotics in an aqueous solution and a solid film.