Abstract Epinephrine (EP) is one of the key neurotransmitter, which plays a vital role in the central nervous system. Current research report designates the development of biosensor based on the modification of glassy carbon electrode (GCE) with multi walled carbon nano tubes (MWCNTs) followed by drop casting of Tyrosinase (Ty) enzyme (Ty/MWCNTs/GCE) towards the sensitive monitoring of EP. The electrochemical behavior of EP at Ty/MWCNTs/GCE biosensor was examined and the redox mechanism was proposed. The developed Ty/MWCNTs/GCE was characterized by electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and tafel plot studies. The influence of pH of phosphate buffer solution (PBS) on the electrochemical redox behavior of EP was observed and pH-7.0 was identified as optimal pH value. The electrochemical kinetic parameters such as heterogeneous rate constant, diffusion coefficient and charge transfer coefficient values were evaluated. The limit of detection and limit of quantification values were evaluated. The low apparent Michaelis – Menten constant (Kmapp) was determined as 0.159 mM, demonstrating the immense catalytic activity of Ty enzyme. Repeatable, reproducible and stable nature of the fabricated Ty/MWCNTs/GCE was successfully examined. Finally, the developed biosensor was tested for the practical application in quantification of EP in human serum samples.

中文翻译：

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基于多壁碳纳米管介导的酪氨酸酶电化学生物传感平台的开发、验证和酶动力学评估，用于肾上腺素的伏安监测

摘要 肾上腺素（EP）是重要的神经递质之一，在中枢神经系统中起着至关重要的作用。当前的研究报告指定了基于玻璃碳电极 (GCE) 改性的多壁碳纳米管 (MWCNTs) 然后滴注酪氨酸酶 (Ty) 酶 (Ty/MWCNTs/GCE) 的生物传感器的开发，以实现灵敏监测EP。研究了 EP 在 Ty/MWCNTs/GCE 生物传感器上的电化学行为，并提出了氧化还原机制。开发的 Ty/MWCNTs/GCE 的特征在于电化学技术，如循环伏安法 (CV)、电化学阻抗谱 (EIS) 和塔菲尔图研究。观察了磷酸盐缓冲溶液 (PBS) 的 pH 值对 EP 电化学氧化还原行为的影响，并将 pH-7.0 确定为最佳 pH 值。评估了电化学动力学参数，例如非均相速率常数、扩散系数和电荷转移系数值。评估了检测限和定量值的限。低表观 Michaelis – Menten 常数 (Kmapp) 被确定为 0.159 mM，表明 Ty 酶具有巨大的催化活性。成功检验了所制造的 Ty/MWCNTs/GCE 的可重复性、可再现性和稳定性。最后，对开发的生物传感器在定量人血清样品中的 EP 中的实际应用进行了测试。低表观 Michaelis – Menten 常数 (Kmapp) 被确定为 0.159 mM，表明 Ty 酶具有巨大的催化活性。成功检验了所制造的 Ty/MWCNTs/GCE 的可重复性、可再现性和稳定性。最后，对开发的生物传感器在定量人血清样品中的 EP 中的实际应用进行了测试。低表观 Michaelis – Menten 常数 (Kmapp) 被确定为 0.159 mM，表明 Ty 酶具有巨大的催化活性。成功检验了所制造的 Ty/MWCNTs/GCE 的可重复性、可再现性和稳定性。最后，对开发的生物传感器在定量人血清样品中的 EP 中的实际应用进行了测试。