Fluorescence sensing of amine vapours based on ZnS-supramolecular organogel hybrid films

Abstract

A stable fluorescent ZnS-supramolecular organogel hybrid film was fabricated and investigated for the sensing of volatile organic monoamine and diamine vapour. The film was prepared by placing a supramolecular organogel film incorporated with Zn(Ac)₂ in H₂S atmosphere for 48 h at ambient temperature. The fabrication of the organogel film was achieved by spin-coating of the hot low-molecular-mass gelator (LMMG) dimethylformamide solution onto the surface of a glass plate. The hybrid film exhibits uniform cross-linked nanofibres, as revealed by SEM measurements. The obtained organogel film demonstrated promising performance as a substrate for stabilizing ZnS nanoparticles loaded in the ZnS-supramolecular organogel hybrid film. The quantity of the ZnS nanoparticles embedded in the hybrid film can be conveniently adjusted by the initial concentrations of Zn²⁺. The sensing mechanism of the combination of static and dynamic quenching was elucidated. The sensing performances of the film for common volatile organic compounds were investigated with a detection limit of 11.0 ppm obtained for ethylenediamine vapour. It is found that the sensing response time is strongly related to the volatile performance of the organic amines tested.