Photostable aggregation-induced emission of iridium(III) complex realizing robust and high-resolution imaging of latent fingerprints

Preparation of AIEgens with excellent photostability is of vital importance to acquire the optimal performance of aggregation-induced emission (AIE) and remains challenging. In this paper, a handy structural design strategy based on iridium(III) complexes for the creation of photostable AIEgens is reported. The synergistic effect of phenyl and carbazole improves the rotational activity of substituents, then activates the AIE property of iridium(III) complexes with considerably improved photostability. In addition, prompt and high-resolution imaging of latent fingerprints on tinfoil, glass, plastic, and steel is presented by immersion in an aqueous solution of IrCzPh for 60 s. With the aid of photostable AIE, legible and intact fingerprint images demonstrate ultrahigh definition, which can display down to level 3 of fingerprint details and accurately authenticate individual characteristics. Meanwhile, outstanding anti-aging performance of fingerprint images is emerged with no contrast attenuation under 365 nm irradiation for 60 min or aged in natural light for 7 days. Noteworthily, ultrahigh-contrast dynamic imaging of local fingerprint details is achieved.