Synthesis and application of a water-soluble phosphorescent iridium complex as turn-on sensing material for human serum albumin

A novel water-soluble cyclometallated iridium complex [Ir(pq-COOH)₂FDS]^- (pq-COOH = 2-phenylquinoline-4-carboxylic acid, FDS = 3-(2-pyridyl)-5,6-bis(4-sulfophenyl)-1,2,4-triazine dianions) (abbreviated as Ir) was synthesized and its phosphorescent property was comprehensively studied. It was found that the complex exhibited strong phosphorescence, which peaked at 634 nm in neutral conditions (maximized at pH 8.0). Its phosphorescence decreased with an increase in acidity of the aqueous solution. At pH 2.0, the quenched phosphorescence could be resumed upon the addition of human serum albumin (HSA) because of the hydrophobic and electrostatic interactions between HSA and Ir. Based on this phenomenon, a "turn on" type phosphorescence probe was developed for the detection of HSA. Under optimal conditions, a wide calibration range of 1-280 nM was obtained with a limit of detection of 0.8 nM for HSA. The phosphorescence probe was successfully used for the determination of HSA in blood serum and urine samples.

Ir(iii) complex-based phosphorescence and electrochemiluminescence chemodosimetric probes for Hg(ii) ions with high selectivity and sensitivity

Acetylacetonato Ir(iii) complexes showed turn-on, turn-off, or ratiometric responses in both phosphorescence and electrochemiluminescence channels.

An unusual highly emissive water-soluble iridium lissamine-alanine complex and its use in a molecular logic gate

The interaction of iridium(iii) with a new lissamine rhodamine B sulfonyl derivative, bearing alanine as a building block, (1) with an orange emission in water results in a green highly emissive Ir@1 complex at room temperature. The new Ir@1 complex can sense the toxic Hg(2+) metal ion and cysteine. Based on such properties, a new sophisticated molecular logic gate with three inputs was designed.

A sulfur-free iridium(III) complex for highly selective and multi-signaling mercury(II)-chemosensors

A sulfur-free iridium(III) complex (pbi)2Ir(mtpy) (1) was successfully prepared and adopted as a Hg(II)-chemosensor with high selectivity and sensitivity. Multi-signaling responses towards Hg(II) ions were observed by UV-vis absorption, phosphorescence and electrochemistry measurements. With addition of Hg(II) ions, complex 1 presented quenched emission in its phosphorescence spectrum and the detection limit was as low as 2.5 × 10(-7) M. Additionally, its redox peak currents showed a broad linear relationship with the concentration of Hg(II) ions ranging from 0 to 500 μM, which was beneficial for the quantitative detection. Based on the (1)H NMR and ESI-MS analyses, the probing mechanism was tentatively supposed to be the Hg(2+)-induced changes in the local environment of complex 1. Such a response process was useful for achieving simple and effective detection of Hg(II) ions as well as developing more chemosensors.

Towards an efficient blue emission cationic Ir(iii) complex with azole-type ancillary ligands: a joint theoretical and experimental study

A highly efficient blue emitting cationic Ir(iii) complex based on 1,2,4-triazole-pyridine ligands modified by a simple methyl moiety is reported.

An overview of the recent developments on Hg2+ recognition

Adverse influences of mercury on living organisms are well known. Despite efforts from various regulatory agencies, the build-up of Hg²⁺ concentration in the environment is of serious concern. This necessitates the search for new and efficient reagents for recognition and detection of Hg²⁺ in environmental samples.

Cyclometalated Ir(iii) complexes with styryl-BODIPY ligands showing near IR absorption/emission: preparation, study of photophysical properties and application as photodynamic/luminescence imaging materials

Heteroleptic C^N cyclometalated iridium(iii) complexes showing strong NIR absorption were prepared.

New ‘aggregation induced emission (AIE)’ active cyclometalated iridium(iii) based phosphorescent sensors: high sensitivity for mercury(ii) ions

Strategic design and syntheses of an AIE active bis-cyclometalatediridium(iii) complex were carried out for highly selective and sensitive detection of mercuric ions.