Aggregation-induced emission logic gates based on metal ion sensing of phenanthroline-tetraphenylethene conjugates

Phenanthroline-tetraphenylethene (Phen-1TPE) was synthesized by a typical Suzuki coupling. The aggregation-induced emission (AIE) properties and interactions with metal ions in THF-water (f(w) = 90%) and in THF were investigated. Aggregation-induced emission logic gates were fabricated based on the metal ion sensing of Phen-1TPE conjugates via control of the metal ions and solvents. In THF-water with f(w) = 90%, Phen-1TPE exhibits a strong AIE effect, while the fluorescence is almost totally quenched upon the addition of Cu2+ compared to other metal ions. Phen-1TPE works as an INHIBIT logic gate, with Cu2+ and aggregation (Agg) as the inputs and the fluorescence as the output. The fluorescence can also be quenched in f(w) = 90% by the addition of metal ions (Cd2+, Zn2+, Sn2+ and In3+). In THF, Phen-1TPE exhibits a metal ion-ligand charge transfer (MLCT)-caused fluorescence enhancement by the addition of metal ions (Cd2+, Zn2+, Sn2+ and In3+). Thus it is established that Phen-1TPE works as a dual XOR logic gate with metal ions (Cd2+, Zn2+, Sn2+ and In3+) and Agg as the inputs. The INHIBIT and XOR logic gates were manipulated by utilizing different metal ions and water-THF volume ratios as the inputs, and the fluorescence of Phen-1TPE as the output.