Supported lipid bilayers are a well-developed model system for the study of membranes and their associated proteins, such as membrane channels, enzymes, and receptors. These versatile model membranes can be made from various components, ranging from simple synthetic phospholipids to complex mixtures of constituents, mimicking the cell membrane with its relevant physiochemical and molecular phenomena. In addition, the high stability of supported lipid bilayers allows for their study via a wide array of experimental probes. In this work, we describe a platform for supported lipid bilayers that is accessible both electrically and optically, and demonstrate direct optical observation of the transmembrane potential of supported lipid bilayers. We show that the polarization of the supported membrane can be electrically controlled and optically probed using voltage-sensitive dyes. Membrane polarization dynamics is understood through electrochemical impedance spectroscopy and the analysis of an equivalent electrical circuit model. In addition, we describe the effect of the conducting electrode layer on the fluorescence of the optical probe through metal-induced energy transfer, and show that while this energy transfer has an adverse effect on the voltage sensitivity of the fluorescent probe, its strong distance dependency allows for axial localization of fluorescent emitters with ultrahigh accuracy. We conclude with a discussion on possible applications of this platform for the study of voltage-dependent membrane proteins and other processes in membrane biology and surface science.

支持的脂质双层是一种成熟的模型系统，用于研究膜及其相关蛋白质，例如膜通道、酶和受体。这些多功能模型膜可以由各种成分制成，从简单的合成磷脂到复杂的成分混合物，模仿细胞膜及其相关的物理化学和分子现象。此外，支持的脂质双层的高稳定性允许通过各种实验探针进行研究。在这项工作中，我们描述了一个可通过电学和光学方式访问的支持的脂质双层平台，并演示了对支持的脂质双层的跨膜电位的直接光学观察。我们表明，可以使用电压敏感染料对支撑膜的偏振进行电控制和光学探测。通过电化学阻抗谱和等效电路模型的分析可以了解膜极化动力学。此外，我们通过金属诱导能量转移描述了导电电极层对光学探针荧光的影响，并表明虽然这种能量转移对荧光探针的电压灵敏度有不利影响，但其强烈的距离依赖性允许以超高精度轴向定位荧光发射器。最后，我们讨论了该平台在电压依赖性膜蛋白以及膜生物学和表面科学中其他过程研究中的可能应用。