With the aim of optical sensing of Hg²⁺ in water, a calixarene bearing two dansyl fluorophores was grafted on a large pore mesoporous silica material (SBA-15) via two long alkyl chains containing triethoxysilane groups. The characterization of the obtained material 2-SBA-15 shows that the organized structure is preserved after the post-grafting procedure. A detailed study of the complexing and fluorescence properties of 2-SBA-15 is reported. The functionalized material is able to reversibly detect Hg²⁺ with a response time of a few seconds and a detection limit of 3.3 × 10⁻⁷ mol L⁻¹ in water. Furthermore, this system offers a high selectivity over several interfering cations (Na⁺, K⁺, Ca²⁺, Cu²⁺, Cd²⁺, Pb²⁺).

A new fluorescent molecular sensor based on a calix[4]arene bearing four dansyl groups exhibits very efficient binding in acetonitrile–water for lead and the changes of emission properties allows a detection limit of 4 µg L⁻¹.