A novel AIEE polymer sensor for detection of Hg2+ and Ag+ in aqueous solution

A novel AIEE (aggregation-induced emission enhancement)-active conjugated polymer incorporating thiazole and tetraphenylethene (TPE) was designed and synthesized via Pd-catalyzed Sonogashira coupling reaction. The polymer shows typical AIEE phenomena, and emits green fluorescence in the mixed solvent of tetrahydrofuran (THF) and water, reaching a maximum fluorescence intensity when the fraction of water is 90%. In the aqueous phase (fw = 90%), the polymer sensor exhibits “turn-off” fluorescence quenching responses towards Hg2+ and Ag+ over other cations, such as Li+, K+, Ca2+, Mg2+, Ba2+, Zn2+, Cd2+, Co2+, Ni2+, Pb2+, Cu2+, Al3+ and Fe3+. The obvious fluorescence change (bright yellow to weak emission) can be clearly observed by the naked eyes.