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.