Background: Hydrogen peroxide (H₂O₂) is widely used in various fields and it plays a quintessential role in a variety of biomolecular processes. H2O2 concentration level is an essential biological parameter in monitoring and maintaining the physiological balance of a living cell, and its variation causes some related diseases. Therefore, it is extremely significant to fabricate biosensor with low cost, which can quickly, accurately and sensitively detect H₂O₂ in a wide range. The aims of this paper are to explore a novel electrochemical sensor with high intrinsic peroxidase-like activity, high sensitivity and stability to effectively detect H₂O₂ concentration in real samples.

Methods: The chemically modified electrode LaNiTiO₃-Fe₃O₄/GCE was fabricated based on the nanomaterial LaNiTiO₃-Fe₃O₄ by a simple process, and its electrochemical properties were investigated in the supporting electrolyte of 0.1 M NaOH by the techniques of cyclic voltammetry and currenttime curves on an electrochemical workstation with a conventional three-electrode system.

Results: LaNiTiO₃-Fe₃O₄ nanoparticles show good peroxidase-like activity for H2O2 at a low applied potential of +0.50 V. Under the optimum conditions, the peroxidase biomimetic sensor LaNiTiO₃-Fe₃O₄/GCE exhibited a wide linear response for H₂O₂ oxidation in the range of 0.05 μM - 3.0 mM (R = 0.9994) with a high sensitivity of 3946.2 μA·mM-1·cm-2 and fast response time of 2 s; besides, the detection limit of H₂O₂ was found to be ca. 5.15 nM (S/N = 3). Moreover, the biosensor exhibited good repeatability, stability and anti-interference. Satisfactory results were obtained when the sensor LaNiTiO₃-Fe₃O₄/GCE was applied to determine H₂O₂ in real samples. All of these results provide support to practical application.

Conclusion: A highly sensitive peroxidase biomimetic sensor based on LaNiTiO₃-Fe₃O₄ with nanoscaled material has been successfully explored, and shows good activity for H₂O₂. The proposed biosensor with simple and low cost exhibited excellent advantages of quick response, wide linear range, low detection limit, high sensitivity, long-term stability and good anti-interference ability, which offer promising applications.

背景：过氧化氢（H ₂ O ₂）被广泛用于各个领域，并且在各种生物分子过程中起着至关重要的作用。H2O2浓度水平是监测和维持活细胞生理平衡的重要生物学参数，其变化会引起一些相关疾病。因此，制造低成本，能够快速，准确且灵敏地检测大范围的H ₂ O _2的生物传感器具有极其重要的意义。本文的目的是探索一种新型的具有高固有过氧化物酶活性，高灵敏度和稳定性的电化学传感器，以有效地检测实际样品中的H ₂ O ₂浓度。

方法：基于纳米材料LaNiTiO ₃ -Fe ₃ O _4，通过简单的工艺制备了化学修饰的电极LaNiTiO ₃ -Fe ₃ O ₄ / GCE ，并在0.1 M NaOH的支持电解质中研究了其电化学性能。常规三电极系统在电化学工作站上的伏安法和电流时间曲线图

结果：LaNiTiO ₃ -Fe ₃ O ₄纳米颗粒在+0.50 V的低施加电势下对H2O2表现出良好的过氧化物酶样活性。在最佳条件下，过氧化物酶仿生传感器LaNiTiO ₃ -Fe ₃ O ₄ / GCE表现出宽线性H ₂ O ₂氧化的响应在0.05μM-3.0 mM（R = 0.9994）的范围内，具有3946.2μA·mM-1·cm-2的高灵敏度和2 s的快速响应时间；此外，H ₂ O ₂的检出限被发现是大约。5.15 nM（S / N = 3）。此外，该生物传感器表现出良好的可重复性，稳定性和抗干扰性。当使用传感器LaNiTiO ₃ -Fe ₃ O ₄ / GCE测定实际样品中的H ₂ O ₂时，可获得令人满意的结果。所有这些结果为实际应用提供了支持。

结论：成功开发了一种以LaNiTiO ₃ -Fe ₃ O ₄为纳米材料的高灵敏度过氧化物酶仿生传感器，对H ₂ O ₂具有良好的活性。提出的简单，低成本的生物传感器具有响应速度快，线性范围宽，检测限低，灵敏度高，长期稳定性好，抗干扰能力强等优点，具有广阔的应用前景。