Pyrogallol‐Stabilized Iridium Nanoclusters With Laccase‐Like Activity for Dual Mode Detection of 2,4‐Dichlorophenol

Metal nanoclusters (MNCs) have attracted widespread attention due to their unique subnanometer size, tunable fluorescence emission, and excellent biocompatibility. However, the enzyme-like activity and the optical properties of MNCs are rarely exploited simultaneously. Here, iridium nanoclusters (Py-IrNCs) with excellent fluorescence properties and the laccase-like activity were synthesized by the reduction of IrCl₃ with NaBH₄ in the presence of pyrogallol. The laccase activity of Py-IrNCs exhibited in the catalytic transformation of 2,4-dichlorophenol (2, 4-DP) is substantially superior to that of natural laccase, which is manifested by the fact that the amount of Py-IrNCs was only 2.5% of natural laccase to achieve the same catalytic performance. In the coexisting of 4-aminoantipyrine (4-AP), a distinct color change and quench of fluorescence were observed; thus, a sensitive colorimetric and fluorescence dual-mode determination of 2,4-DP was achieved with a linear range of 0-40 μM and a limit of detection of 0.5 μM. The dual-mode detections can be mutually verified, which effectively improved the reliability of the analysis, demonstrating a promising application potential of Py-IrNCs in pollutant determination.