A Multivalent Supramolecular Assembly for the Detection and Removal of Pd²

Palladium, a harmful environmental contaminant, necessitates the development of rapid and sensitive methods for its detection and removal. In this work, a yellow-emissive multivalent supramolecular assembly was developed through the self-assembly of a triphenylamine derivative (G) and nor-seco-cucurbit[10]uril (ns-Q[10]). G and ns-Q[10] form a network assembly with yellow fluorescence emission through supramolecular assembly. In this assembly, the distorted and electron-rich G molecules act as the cross-linking units. This supramolecular assembly can be used for the fluorescence detection of Pd²⁺, and its detection limit can reach 3.43 × 10^-7 mol/L. The fluorescence quenching mechanism is attributed to coordination between the assembly network and Pd²⁺ ions, leading to attenuation through a combination of dynamic quenching and charge transfer. Furthermore, the removal behavior was fitted using isotherms based on the Langmuir model, and the maximum removal capacity of the G/ns-Q[10] assembly for Pd²⁺ ions was determined to be 602.17 mg/g. Within an initial Pd²⁺ concentration range of 8.87-88.67 mg/L, the removal efficiency remained between 93.77% and 99.87%, indicating excellent removal performance over a wide concentration range. Therefore, this work presents a supramolecular strategy for the detection and removal of Pd²⁺ ions.