A novel AIE-active camphor-based fluorescent probe for simultaneous detection of Al3+ and Zn2+ at dual channels in living cells and zebrafish.

A novel dual-functional probe N'-(2-hydroxy-5-((4,7,7-trimethyl-3-oxobicyclo[2.2.1] heptan-2-ylidene)methyl) benzylidene)picolinohydrazide (PSH) was constructed from natural camphor. This probe showed strong yellow-green fluorescence at 535 nm due to its aggregation-induced emission (AIE) feature. Interestingly, the probe PSH displayed a significant turn-on fluorescence response towards Al3+ (green fluorescence at 500 nm) and Zn2+ (orange fluorescence at 555 nm) at two different emissive channels. The detection limits of PSH towards Al3+ and Zn2+ were found to be 12.1 nM and 14.2 nM, respectively. PSH exhibited excellent selectivity and anti-interference performance and could distinguish between Al3+/Zn2+ and identify whether Zn2+ exists in the PSH-Al3+ complex by adding ATP. The binding mechanisms between PSH and Al3+/Zn2+ ions were supported by 1H NMR, HRMS analysis, and density functional theory (DFT) calculations. Based on its outstanding sensing properties, the probe PSH was used to establish molecular logic function gates. Moreover, the probe PSH could be applied to detect Al3+ and Zn2+ in real environmental water, and fluorescence detection was well demonstrated by test strips. Furthermore, the probe PSH was employed for imaging Al3+ and Zn2+ in HeLa cells and zebrafish.