Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Department of Electrical & Electronic Engineering, Yonsei University, Seoul, Republic of Korea.
Nat Commun. 2021 Jun 18;12(1):3741. doi: 10.1038/s41467-021-24122-8.
Despite technological advances in biomolecule detections, evaluation of molecular interactions via potentiometric devices under ion-enriched solutions has remained a long-standing problem. To avoid severe performance degradation of bioelectronics by ionic screening effects, we cover probe surfaces of field effect transistors with a single film of the supported lipid bilayer, and realize respectable potentiometric signals from receptor-ligand bindings irrespective of ionic strength of bulky solutions by placing an ion-free water layer underneath the supported lipid bilayer. High-energy X-ray reflectometry together with the circuit analysis and molecular dynamics simulation discovered biochemical findings that effective electrical signals dominantly originated from the sub-nanoscale conformational change of lipids in the course of receptor-ligand bindings. Beyond thorough analysis on the underlying mechanism at the molecular level, the proposed supported lipid bilayer-field effect transistor platform ensures the world-record level of sensitivity in molecular detection with excellent reproducibility regardless of molecular charges and environmental ionic conditions.
尽管在生物分子检测方面取得了技术进步，但在富含离子的溶液中通过电位测定装置来评估分子相互作用仍然是一个长期存在的问题。为了避免离子屏蔽效应严重降低生物电子设备的性能，我们用单层支撑脂质双层覆盖场效应晶体管的探针表面，并通过在支撑脂质双层下方放置无离子水层，实现了来自受体-配体结合的可观的电位信号，而与体积庞大的溶液的离子强度无关。高能量 X 射线反射率以及电路分析和分子动力学模拟揭示了生化发现，即有效的电信号主要源于受体-配体结合过程中脂质的亚纳米级构象变化。除了在分子水平上对基础机制进行彻底分析外，所提出的支撑脂质双层-场效应晶体管平台确保了在分子检测方面具有创纪录的灵敏度和出色的重现性，而与分子电荷和环境离子条件无关。
