Selective and sensitive detection of Zn(II) in solution and nanofibers using phosphorescent iridium(III) complexes

Two iridium(III) complexes [(L1)2Ir(tpip)] (Ir1, L1 = 6-phenylnicotinaldehyde), [(L2)2Ir(tpip)] (Ir2, L2 = 6-(4-(trifluoromethyl)phenyl)nicotinaldehyde), bearing tetraphenylimidodiphosphinate (tpip) ancillary ligand, were developed as efficient luminescent sensor for the detection of Zn2+. Ir1 and Ir2 exhibited broad emission bands peaking at 613 nm and 603 nm with PLQY of 0.32 and 0.57 and lifetimes of 1.8 and 1.3 mu s, respectively. They showed excellent response to Zn2+ with a high sensitivity and selectivity, low detection limit on the order of 10-7 M and short response time on seconds in solution. Such an outstanding detection was based on significant blue shifts of their emissions. Nanofibers with these complexes were fabricated by electrospinning to realize the on -site detection of Zn2+ in solid-phase with similar colorimetric changes of their phosphorescence as in solution.

Automated summary

Two iridium(III) complexes [(L1)2Ir(tpip)] (Ir1) and [(L2)2Ir(tpip)] (Ir2) with tetraphenylimidodiphosphinate (tpip) ancillary ligand were developed as efficient luminescent sensors for Zn2+ detection. Both complexes exhibited broad emission bands peaking at 613 nm and 603 nm, with PLQY of 0.32 and 0.57, and lifetimes of 1.8 and 1.3 μs, respectively. They showed excellent sensitivity and selectivity towards Zn2+ with a low detection limit of around 10-7 M and fast response time in solution. Nanofibers of these complexes were fabricated for on-site detection of Zn2+ in solid-phase, showing similar colorimetric changes as in solution.