In this study, an innovative strategy was proposed for the electrocatalytical reduction and enzymatic biosensing of hydrogen peroxide (H₂O₂) using chronoamperometry technique. For the first time, immobilization of horseradish peroxidase (HRP) in polydopamine-modified magnetic nanoparticles (PDA-MNPs) was successfully performed. Also, poly(l-arginine/toluidine blue) film–modified glassy carbon electrode was constructed through co-electropolymerization of l-arginine and toluidine blue on the surface of GCE using cyclic voltammetry technique. The engineered hybrid thin film provides strong functionalities for efficient grafting of PDA-MNPs which, in turn, enable the covalent immobilization of HRP. The proposed biosensor was used for the detection of H₂O₂ in the range of 0.5-30 μM with a low limit of quantification 0.23 μM. It also was successfully applied for the investigation of hydrogen peroxide in human plasma samples.

中文翻译：

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使用固定在聚（精氨酸-甲苯胺蓝）-Fe3O4 纳米颗粒修饰的聚多巴胺表面的 HRP 对人血浆样品中过氧化氢 (H2O2) 的酶促识别；一种新型生物传感器

在这项研究中，提出了一种使用计时电流法技术对过氧化氢 (H ₂ O _{2 ) 进行电催化还原和酶促生物传感的创新策略。}首次成功地将辣根过氧化物酶（HRP）固定在聚多巴胺修饰的磁性纳米颗粒（PDA-MNPs）中。此外，通过l的共电聚合构建了聚（l-精氨酸/甲苯胺蓝）薄膜修饰的玻碳电极。-精氨酸和甲苯胺蓝在 GCE 表面上使用循环伏安法技术。工程化的杂化薄膜为 PDA-MNPs 的有效接枝提供了强大的功能，这反过来又使 HRP 的共价固定成为可能。所提出的生物传感器用于检测0.5-30 μM范围内的H ₂ O _{2 ，​​定量下限为0.23 μM。}它还成功地应用于人体血浆样品中过氧化氢的研究。