Phosphorescent iridium(III) complex based photoluminescence sensor for sensitive and selective detection of picric acid

The sensitive and selective detection of picric acid is of great importance to the society safety and human health. In this paper, a novel blue emissive iridium(III) complex FIrPicOMPBHCz containing carbazole moieties has been successfully synthesized and applied in photoluminescence (PL) sensing towards nitroaromatic explosives (e.g. PA, TNB, DNP, TNT, DNT, NP, NBA, NB) detection. The PL emission of FIrPicOMPBHCz could be quenched by the explosives with different extents. Among these, the quenching constant K-sv towards PA is the highest, which is 1.9 x 10(4) M-1, with one to two orders of magnitude higher than that of other nitroaromatics, thus demonstrating a selective PL detection of PA. The sensing mechanism is based on the excited state electron transfer process, by analyzing the UV-vis absorption, excitation and PL spectra and cyclic voltammogram results. In addition, the paper strip tests indicate a great potential of FIrPicOMPBHCz as a solid PL sensor for PA.