We developed ion-selective field-effect transistor (FET) sensors with floating electrodes for the monitoring of the potassium ion release by the stimulation of nicotinic acetylcholine receptors (nAChRs) on PC12 cells. Here, ion-selective valinomycin-polyvinyl chloride (PVC) membranes were coated on the floating electrode-based carbon nanotube (CNT) FETs to build the sensors. The sensors could selectively measure potassium ions with a minimum detection limit of 1 nM. We utilized the sensor for the real-time monitoring of the potassium ion released from a live cell stimulated by nicotine. Notably, this method also allowed us to quantitatively monitor the cell responses by agonists and antagonists of nAChRs. These results suggest that our ion-selective CNT-FET sensor has potential uses in biological and medical researches such as the monitoring of ion-channel activity and the screening of drugs.

中文翻译：

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离子选择性碳纳米管场效应晶体管，用于监测药物对活细胞中烟碱乙酰胆碱受体活化的影响。

我们开发了带有浮动电极的离子选择性场效应晶体管（FET）传感器，用于通过刺激PC12细胞上的烟碱乙酰胆碱受体（nAChRs）监测钾离子释放。在此，将离子选择性缬氨霉素-聚氯乙烯（PVC）膜涂覆在基于浮动电极的碳纳米管（CNT）FET上，以构建传感器。传感器可以选择性检测钾离子，最低检测限为1 nM。我们利用传感器实时监测从尼古丁刺激的活细胞中释放的钾离子。值得注意的是，这种方法还使我们能够定量监测nAChRs激动剂和拮抗剂的细胞反应。