Selective and sensitive fluorescent probes for metal ions based on AIE dots in aqueous media

Abstract

Multi-functional fluorescent probes have attracted more interest recently. Herein, two simple fluorescent probes (FAS and DPAS) from AIEgens with the ESIPT process of salicylaldehyde Schiff-base structures are developed. The aggregates of FAS and DPAS exhibit good selectivity and sensitivity towards Cu²⁺ in aqueous media without any water-miscible organic solutions as buffers. Their larger association constants and appropriate hydrophilic and hydrophobic properties play key roles in achieving lower detection limits. Based on their fluorescence on/off processes in the presence or absence of Hg²⁺, the composite probes are further prepared.