Abstract A highly sensitive acetylcholinesterase electrochemical biosensor for the determination of acetylcholine (Ach), a neurotransmitter essential for processing memory and learning, the lack of which is associated with Alzheimer's disease, has been developed. AChE was immobilized on a poly(neutral red) film formed by potential cycling electropolymerisation on Fe2O3 magnetic nanoparticle modified electrodes in acid-doped ethaline deep eutectic solvent. The influence of different acid dopants with anions NO3−, SO42−, Cl−, ClO4 on the rate of growth and electrochemical properties of the polymer films was studied and compared with PNR growth in aqueous solution. Modified electrode characterisation was carried out by voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. Acetylcholinesterase enzyme was immobilized, using glutaraldehyde cross-linking, on the best polymer film Fe2O3 nanoparticle support, polymer formed in nitric acid–doped ethaline. The novel biosensor exhibited a limit of detection of 1.04 μM for Ach, lower than reported in the literature, and had excellent reproducibility and long-term stability. It was successfully applied to the determination of ACh in synthetic urine, with excellent recoveries, which makes it a promising biosensor for clinical diagnosis of Alzheimer's disease.

中文翻译：

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基于乙酰胆碱酯酶/聚（中性红）的新型乙酰胆碱生物传感器——深共熔溶剂/Fe2O3纳米颗粒修饰电极

摘要 已开发出一种用于测定乙酰胆碱 (Ach) 的高灵敏度乙酰胆碱酯酶电化学生物传感器，乙酰胆碱是处理记忆和学习必不可少的神经递质，缺乏乙酰胆碱酯酶与阿尔茨海默病有关。AChE 被固定在聚（中性红）膜上，该膜是通过在酸掺杂的乙醇深共熔溶剂中的 Fe2O3 磁性纳米粒子修饰电极上的电位循环电聚合形成的。研究了具有阴离子 NO3-、SO42-、Cl-、ClO4 的不同酸掺杂剂对聚合物薄膜的生长速率和电化学性能的影响，并与水溶液中的 PNR 生长进行了比较。通过伏安法、电化学阻抗谱和扫描电子显微镜进行改良的电极表征。使用戊二醛交联，乙酰胆碱酯酶被固定在最好的聚合物膜 Fe2O3 纳米颗粒载体上，聚合物在掺有硝酸的乙醇中形成。这种新型生物传感器的 Ach 检测限为 1.04 μM，低于文献报道，并且具有出色的重现性和长期稳定性。它已成功应用于合成尿液中乙酰胆碱的测定，回收率极好，使其成为临床诊断阿尔茨海默病的有前途的生物传感器。