Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu Province 214122, P. R. China.
J Mater Chem B. 2023 Mar 22;11(12):2770-2777. doi: 10.1039/d2tb02798d.
Iridium nanoparticles with an average size of 1.7 nm (Tar-IrNPs) were synthesized by the reduction of IrCl with NaBH in the presence of tartaric acid. As prepared Tar-IrNPs showed not only oxidase, peroxidase and catalase activities but also exhibited unprecedented laccase-like activity, which can catalyze the oxidation of the substrates -phenylenediamine (OPD) and -phenylenediamine (PPD) accompanied by significant color changes. The superb catalytic performance is evidenced by the fact that Tar-IrNPs can achieve better laccase-like activity with only 2.5% of the dosage of natural laccase. Furthermore, they also exhibited superior thermal stability and broader pH adaptability (2.0-11) over that of natural laccase. Tar-IrNPs can retain more than 60% of their initial activity at 90 °C, while the natural laccase has totally lost its activity at 70 °C. At a prolonged reaction time, the oxidation products of OPD and PPD can form precipitates due to oxidation induced polymerization. Thus Tar-IrNPs have been successfully used for the determination and degradation of PPD and OPD.
平均粒径为 1.7nm 的铱纳米粒子（Tar-IrNPs）通过在酒石酸存在下用 NaBH4 还原 IrCl 合成。所制备的 Tar-IrNPs 不仅表现出氧化酶、过氧化物酶和过氧化氢酶活性，而且还表现出前所未有的漆酶样活性，可催化底物邻苯二胺（OPD）和对苯二胺（PPD）的氧化，同时伴随着明显的颜色变化。Tar-IrNPs 的卓越催化性能表现在，与天然漆酶相比，只需 2.5%的天然漆酶用量即可实现更好的漆酶样活性。此外，它们还表现出优于天然漆酶的热稳定性和更宽的 pH 适应性（2.0-11）。Tar-IrNPs 在 90°C 时仍能保留超过 60%的初始活性，而天然漆酶在 70°C 时已完全失活。在延长的反应时间内，由于氧化诱导聚合，OPD 和 PPD 的氧化产物会形成沉淀物。因此，Tar-IrNPs 已成功用于 PPD 和 OPD 的测定和降解。
