A highly selective and sensitive Zn(ii) coordination polymer luminescent sensor for Al3+ and NACs in the aqueous phase

Abstract

A novel coordination polymer Zn(DMA)(TBA) (1) (H₂TBA = 4-(1H-tetrazol-5-yl)-benzoic acid) features a unique two-dimensional (2D) network structure, exhibiting excellent luminescence and good stability in both water and other organic solvents. 1 shows excellent selectivity, fast detection time and high sensitivity (detection limit, 1.97 × 10⁻⁶ M) for Al³⁺ in the aqueous phase via fluorescence enhancement, which represents a rare example in the reported sensors for Al³⁺ detection. It is worth noting that 1 not only exhibits a highly selective fluorescence enhancement (turn on) effect for Al³⁺ in aqueous solution, but can also resist the interference of other metal ions. Meanwhile, 1 can act as a promising functional fluorescent sensor for detecting and recognizing trace nitroaromatic explosives (NACs) through fluorescence quenching with high selectivity and sensitivity in aqueous solutions. Experimental and theoretical calculations indicate that the luminescence quenching is attributed to an electron and resonance energy transfer between CPs and analytes.