Disposable-micropipette tip supported electrified liquid-organogel interface as a platform for sensing acetylcholine

• Published in: Analyst (London) 2023-03, Vol.148 (7), p.1451-1459
• Main Authors: Sudalaimani, S, Arun, S, Esokkiya, A, Sanjeev Kumar, K, Sivakumar, C, Giribabu, K
• Format: Article
• Language: English
• Subjects: Calixarenes; Choline; Configurations; Interfaces; Oxidation; Sensitivity; Solid electrodes
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d2an01663j

Sensing acetylcholine has been predominantly based on enzymatic strategies using acetylcholine esterase and choline oxidase because of its electrochemical inertness. Electrified liquid-liquid interfaces are not limited to oxidation/reduction processes, and can be utilized to detect non-redox molecules which cannot be detected using conventional solid electrodes. In this study, a disposable micropipette tip based liquid-organogel interface, in the presence/absence of calixarene has been developed as a platform for sensing acetylcholine. We also explored a liquid-liquid interface approach for sensing acetylcholine using a pre-pulled glass micropipette. In both approaches, the configuration, i.e. , liquid-organogel and liquid-liquid interface-current linearly increases during the backward transfer of acetylcholine. The simple and facilitated ion transfer of acetylcholine across the liquid-organogel exhibited a linear range of 10-50 μM and 1-30 μM with a detection limit of 0.18 μM and 0.23 μM and a sensitivity of 9.52 nA μM −1 and 9.20 nA μM −1 , respectively. Whereas, the detection limit of simple and facilitated ion transfer of liquid-liquid interface using pre-pulled glass micropipette was found to be 0.42 μM and 0.13 μM with a sensitivity of 5 × 10 −3 nA μM −1 and 3.39 × 10 −2 nA μM −1 . The results indicate that the liquid-organogel configuration supported on a disposable micropipette tip without any pre-fabrication is highly suitable for electrified soft interface sensing applications. A disposable micropipette tip based liquid-organogel interface, in the presence/absence of calixarene has been developed as a platform for sensing acetylcholine and is highly suitable for electrified soft interface sensing applications.