Novel AIE-active ratiometric fluorescent probes for mercury( ii ) based on the Hg 2+ -promoted deprotection of thioketal, and good mechanochromic properties

Novel AIE-active ratiometric fluorescent probes for Hg 2+ were synthesized, which combined the advantages of the excellent luminescence properties of AIEgens in the solid state and the high selectivity of the Hg 2+ -promoted deprotection reaction. Upon testing with mercury ions, the luminescent color changed from sky blue to yellow-green almost immediately, while other metal ions (Ag + , Fe 3+ , Cu 2+ , Pb 2+ , Co 2+ , Cr 3+ , Al 3+ , Cd 2+ , Mg 2+ , Mn 2+ , Ba 2+ , Fe 2+ , Ca 2+ , Ni 2+ , Zn 2+ , Li + , K + , and Na + ) caused no disturbance to the sensing process. Furthermore, the fabricated test strips reported the presence of Hg 2+ ions with the detection limit as low as 1 × 10 −5 M. Moreover, the synthesized AIEgens showed reversible mechanochromic properties with high color contrast, suggesting that they could have additional promising applications in optoelectronic devices.