A novel cyclometallated iridium(III) complex based dual-mode phosphorescent probe for detection of acidity and bovine serum albumin

摘要: A novel phosphorescent, water-soluble cyclometallated iridium complex [(fppy)2Ir(BQCOOH)] (fppy = 4-(2-pyridyl) benzaldehyde, BQCOOH 2,2′-biquinoline-4,4-dicarboxylic acid) (Ir-C) was synthesized and characterized. Analysis found that Ir-C exhibited strong orange-red phosphorescence, which peaked at 630 nm under alkaline conditions remained stable (pH > 7.0). Its response signal decreased with the increasing acidity of aqueous system. worked as a quencher luminescence nitrogen-doped carbon quantum dots (N-CQDs) an electron transfer mechanism, prepared N-CQDs were introduced into system to prepare visual ratiometric pH probe. Due error single emission probes in different environments, probe is more advantageous for accurate simple detection water. At 2.5, quenched can be restored subsequent addition bovine serum albumin (BSA) due several interactions between BSA, mainly electrostatic interactions, hydrophobic deprotonation protonation ligand. Based on this observed phenomenon, “turn on” kind luminescent sensor constructed quantification BSA. Under optimal conditions, wide linear range 20–140 nM obtained limit (LOD) 7 nM.