A turn-on fluorescent chemosensor based on acylhydrazone for sensing of Mg2+ with a low detection limit

Abstract

A novel highly selective chemosensor for Mg²⁺ ions based on the naphthalene group as the fluorophore has been designed and synthesized, which shows a fluorescence turn-on response from colorless to green for Mg²⁺ ions in DMSO–H₂O solutions. L could perform as an “OFF–ON” molecular switch, which was cyclically controlled by Mg²⁺ and EDTA. Moreover, further study demonstrated that the detection limit for the fluorescence response of L to Mg²⁺ was down to 9.2 × 10⁻¹⁰ M, which was lower than with other sensors for Mg²⁺. Test strips based on L were also fabricated, which could act as a convenient and efficient Mg²⁺ test kit. The sensor L could detect Mg²⁺ in two different sources of water, distilled and tap water.