A dual chemosensor for both Cu~(2+) and Al~(3+): A potential Cu~(2+) and Al~(3+) switched YES logic function with an INHIBIT logic gate and a novel solid sensor for detection and extraction of Al~(3+) ions from aqueous solution

摘要

A simple 4-nitrosalicylaldimine-based receptor equipped with rhodamine B moiety (RB-HN) has been designed and synthesized as an "OFF-ON-OFF" dual sensor for the detection of Cu~(2+) and Al~(3+) ions, which exhibits high sensitivity over other metal ions. The chemosensor RB-HN demonstrates selective optical recognition for Cu~(2+) and fluorescence recognition for Al~(3+) over commonly coexistent metal ions in DMSO-H_2O media. The LODs of the RB-HN for Cu~(2+) and Al~(3+) were 4.726 × 10~(-7) and 4.43 × 10~(-7) M, respectively. A coordination mode with 1:1 stoichiometry was proposed between RB-HN and Cu~(2+)/Al~(3+) by the ~1H NMR binding studies. The RB-HN complex with Cu~(2+) and Al~(3+) ions exhibits "turn on-off" behavior and is highly reversible with EDTA. In addition, the UV-vis and fluorescence changes of RB-HN by the inputs of Cu~(2+) and Al~(3+) have been used to construct a combinational logic circuit at the molecular level. Moreover, a novel selective and sensitive solid sensor (PEGDMA-RB-HN) was designed to detect and extract Al~(3+) ions from aqueous solution. Furthermore, the sensitivity of the solid sensor was demonstrated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The extracting capacity of the solid sensor was validated with ICP-AES, and it was significantly lower than the WHO recommendations for drinking water.