A new amperometric biosensor for hydrogen peroxide (H₂O₂) and superoxide anion (SO) has been developed. The biosensor developed uses cytochrome c (Cyt c) modified glassy carbon electrodes coupled with electrochemically reduced graphene oxide (ErGO). To immobilize Cyt c, the “one step” electrochemical deposition of vertically aligned and ErGO (VAErGO) has been performed by using a pulse reverse technique, thus resulting in a very simple and efficient system. The well-established vertical alignment of ErGO was confirmed by atomic force microscopy and the electrochemical characteristics of the biosensor were investigated by cyclic voltammetric, electrochemical impedance spectroscopy and amperometric techniques. The surface coverage (Γ) of immobilized Cyt c was effectively increased by the vertical alignment of ErGO and found to be 1.03 × 10⁻¹⁰ mol cm⁻². The direct electron transfer property of Cyt c was also improved by VAErGO and the heterogeneous electron transfer rate constant (k_et) was estimated to be 6.40 s⁻¹. To detect H₂O₂ and SO, amperometric measurements were carried out at different operating potentials (0.0 V vs. Ag/AgCl for H₂O₂ and +0.2 V for SO). The sensitivity and detection limit for H₂O₂ were found to be 46.3 μA mM⁻¹ cm⁻² and 2.3 μM, and for SO were found to be 32.1 μM nA⁻¹ cm⁻² and 6.84 nM s⁻¹, respectively. Additionally, the designed biosensor exhibited strong anti-interference ability and satisfactory reproducibility.

中文翻译：

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通过在玻璃碳电极上固定垂直排列并电化学还原的氧化石墨烯的细胞色素c进行电化学活性氧种类检测

已开发出一种用于过氧化氢（H ₂ O ₂）和超氧阴离子（SO）的新型安培生物传感器。开发的生物传感器使用细胞色素c（Cyt c）修饰的玻璃碳电极和电化学还原的氧化石墨烯（ErGO）。固定Cyt c，已经通过使用脉冲反向技术进行了垂直排列和ErGO（VAErGO）的“一步”电化学沉积，因此得到了一个非常简单而有效的系统。原子力显微镜证实了ErGO良好的垂直排列，并通过循环伏安法，电化学阻抗谱和安培技术研究了生物传感器的电化学特性。通过ErGO的垂直取向有效地固定了Cyt c的表面覆盖率（Γ）为1.03×10 ^-10 mol cm ^-2。Cyt c的直接电子转移性质通过VAErGO也改善了该常数，异质电子传输速率常数（k_等）估计为6.40 s ^-1。为了检测H ₂ O ₂和SO，在不同的工作电势下进行安培测量（对于H ₂ O ₂为0.0 V对Ag / AgCl，对于SO为+0.2 V）。发现H ₂ O ₂的灵敏度和检测限为46.3μAmM ^-1 cm ^-2和2.3μM，对SO的灵敏度和检测极限为32.1μMnA ^-1 cm ^-2和6.84 nM s ^-1， 分别。此外，设计的生物传感器显示出强大的抗干扰能力和令人满意的重现性。