School of Biomedical Engineering, Korea University, Seoul 02841, Korea.
Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, Seoul 02447, Korea.
Biosensors (Basel). 2022 Apr 27;12(5):279. doi: 10.3390/bios12050279.
For decades, acetylcholine (Ach) has been considered a critical biomarker for several degenerative brain diseases, including Alzheimer's, Parkinson's disease, Huntington's disease, and schizophrenia. Here, we propose a wafer-scale fabrication of polyaniline (PAni)-grafted graphene-based field-effect transistors (PGFET) and their biosensing applications for highly sensitive and reliable real-time monitoring of Ach in flow configuration. The grafted PAni provides suitable electrostatic binding sites for enzyme immobilization and enhances the pH sensitivity (2.68%/pH), compared to that of bare graphene-FET (1.81%/pH) for a pH range of 3-9 without any pH-hysteresis. We further evaluated the PGFET's sensing performance for Ach detection with a limit of detection at the nanomolar level and significantly improved sensitivity (~103%) in the concentration range of 108 nM to 2 mM. Moreover, the PGFET exhibits excellent selectivity against various interferences, including glucose, ascorbic acid, and neurotransmitters dopamine and serotonin. Finally, we investigated the effects of an inhibitor (rivastigmine) on the AchE activity of the PGFET. From the results, we demonstrated that the PGFET has great potential as a real-time drug-screening platform by monitoring the inhibitory effects on enzymatic activity.
几十年来，乙酰胆碱 (Ach) 一直被认为是几种退行性脑疾病的关键生物标志物，包括阿尔茨海默病、帕金森病、亨廷顿病和精神分裂症。在这里，我们提出了一种基于聚苯胺 (PAni)-接枝石墨烯场效应晶体管 (PGFET) 的晶圆级制造方法及其生物传感应用，用于在流动配置中高度灵敏和可靠地实时监测 Ach。与裸石墨烯场效应晶体管 (1.81%/pH) 相比，接枝的 PAni 为酶固定提供了合适的静电结合位点，并提高了 pH 灵敏度 (2.68%/pH)，pH 范围为 3-9 时没有任何 pH 滞后。我们进一步评估了 PGFET 对 Ach 检测的传感性能，检测限达到纳摩尔水平，在 108 nM 至 2 mM 的浓度范围内灵敏度显著提高 (~103%)。此外，PGFET 对各种干扰物（包括葡萄糖、抗坏血酸以及神经递质多巴胺和 5-羟色胺）表现出优异的选择性。最后，我们研究了抑制剂 (利凡斯的明) 对 PGFET 中 AchE 活性的影响。结果表明，PGFET 通过监测对酶活性的抑制作用，具有作为实时药物筛选平台的巨大潜力。
