Novel fluorescent probe for sequential recognition of Zn2+ and pyrophosphate in aqueous based on aggregation-induced emission

A new fluorescent probe (E)-4-(4-([2,2':6',2''-terpyridin]-4'-yl)styryl)-1-dodecylpyridin-1-ium (TPy-SD), with the aggregation-induced emission (AIE) property in aqueous solution, has been synthesized and characterized. The new probe, TPy-SD exhibited excellent selectivity and sensitivity towards Zn2+ with a relatively low detection limit (1.76 x10-7 M). The addition of Zn2+ is thought to disrupt the AIE property of TPy-SD, thereby leading to a fluorescence blue shift. Interestingly, the complex of probe TPy-SD with Zn2+ (Zn (II) TPy-SD), with molar ratio of 1:1, can be used as a simple, sensitive, and rapid means for the detection of pyrophosphates (PPi) in solution (water/DMSO = 99:1). As evidenced by transmission electron microscopy (TEM), dynamic light scattering (DLS) and fluorescence emission spectroscopy, this detection is thought to be due to the strong affinity between PPi and Zn2+, which brings out Zn2+ from the coordination cavity of chemical sensor TPy-SD, thus realizing the detection and recognition of PPi. Therefore, the new AIE fluorescent probe can be used as a dual probe for the detection of cations and anions