This paper reports on enzyme-like catalytic properties of polyethylene glycol-functionalized poly(N-phenylglycine) (PNPG-PEG) nanoparticles, which have not been explored to date. The developed nanoparticles have the ability to display great inherent peroxidase-like activity at very low concentrations, and are able to catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) substrate in presence of hydrogen peroxide (H₂O₂). The oxidized product of TMB has a deep blue color with a maximum absorbance at ~655 nm. The PNPG-PEG nanoparticles exhibit K_m values of 0.2828 for TMB and 0.0799 for H₂O₂, indicating that TMB oxidation takes place at lower concentration of H₂O₂ in comparison to other nanozymes. Based on the known mechanism of H₂O₂ oxidation by hexavalent chromium [Cr(VI)] ions to generate hydroxyl radicals (^•OH), these nanoparticles were successfully applied for the colorimetric sensing of Cr(VI) ions. The sensor achieved good performance for Cr(VI) sensing with detection limits of 0.012 μM (0.01–0.1 μM linear range) and 0.52 μM (0.05–12.5 μM linear range). The detection scheme was highly selective, and successfully applied for the detection of Cr(VI) in real water samples.

本文报道了聚乙二醇官能化的聚（N-苯基甘氨酸）（PNPG-PEG）纳米粒子的酶样催化性能，迄今为止尚未进行探索。所开发的纳米颗粒具有在非常低的浓度下显示出巨大的固有过氧化物酶样活性的能力，并且能够在过氧化氢（H ₂）存在下催化3,3'，5,5'-四甲基联苯胺（TMB）底物的氧化O ₂）。TMB的氧化产物为深蓝色，在〜655 nm处具有最大吸收率。PNPG-PEG纳米颗粒的Tm的K _m值为0.2828，H ₂ O _2的K _m值为0.0799 ，表明TMB氧化发生在较低的H ₂ O ₂浓度下。与其他纳米酶相比。基于六价铬[Cr（VI）]离子将H ₂ O ₂氧化生成羟基自由基（^• OH）的已知机理，这些纳米颗粒已成功用于Cr（VI）离子的比色传感。该传感器的Cr（VI）感测性能良好，检测极限为0.012μM（0.01-0.1μM线性范围）和0.52μM（0.05-12.5μM线性范围）。该检测方案具有很高的选择性，并成功应用于实际水样中的Cr（VI）检测。