Trace Ir(III) complex enhanced electrochemiluminescence of AIE-active Pdots in aqueous media

Trace Ir(III) complex enhanced aggregation-induced electrochemiluminescence (AIECL) of poly-tetraphenylethene (pTPE) in aqueous media was investigated for the first time. The poly-TPE end-capped by Ir(III) complex (Ir@pTPE) and its corresponding model polymer poly-TPE (Ph@pTPE) could be synthesized by Suzuki coupling polymerization reaction of 1,2-bis(4-bromophenyl)-1,2-diphenylethene ( M-1 ) with 1,2-diphenyl-1,2-bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethene( M-2 ) and the continuous Suzuki coupling end-capped reaction of poly-TPE-pinacol boronate with (pq)2Ir(pico)Br and bromobenzene, respectively. Subsequently, the corresponding Ir@pTPE Pdots and Ph@pTPE Pdots encapsulated with poly(styrene- co -maleicanhydride) (PSMA) could be obtained by nanoprecipitation method. Compared with Ph@pTPE Pdots, the Ir@pTPE Pdots with a trace amount of Ir(III) complex (1.34‰ of Ir(III) content, wt) could exhibit 9.9-fold enhancement of the electrochemiluminescence (ECL) signal for visual emission. This work provided a novel strategy on designing highly efficient ECL materials based on trace Ir(III)-end capping AIE-active polymer dots.