Center for BioMicrosystems , Korea Institute of Science and Technology , 5, Hwarang-ro 14-gil, Seongbuk-gu , Seoul 02792 , Republic of Korea.
Department of Mechanical Engineering , Yonsei University , 50, Yonsei-ro, Seodaemun-gu , Seoul 03722 , Republic of Korea.
ACS Appl Mater Interfaces. 2018 Nov 28;10(47):40401-40410. doi: 10.1021/acsami.8b13458. Epub 2018 Nov 15.
Artificial lipid membranes are excellent candidates for new biosensing platforms because their structures are similar to cell membranes and it is relatively easy to modify the composition of the membrane. The freestanding structure is preferable for this purpose because of the more manageable reconstitution of the membrane protein. Therefore, most of the lipid membranes for biosensing are based on two-dimensional structures that are fixed on a solid substrate (unlike floating liposomes) even though they have some disadvantages, such as low stability, small surface area, and potential retention of solvent in the membrane. In this paper, three-dimensional freestanding lipid bilayer (3D FLB) arrays were fabricated uniformly on SU-8 microwells without any toxic solvent. The 3D FLBs have better stability and larger surface area due to their cell-like structure. In order to improve the sealing characteristics of the 3D FLBs, the applied frequency of the ac field was controlled during the electroformation. The 3D FLBs were observed through transparent SU-8 microwell arrays using confocal microscopy and demonstrated perfect sealing until 5.5 days after the electroformation at more than 1 kHz. Also, the details of the sealing of a fixed 3D freestanding lipid structure were discussed for the first time. The unilamellarity and biofunctionality of the 3D FLBs were verified by a transport protein (α-hemolysin) assay.
人工脂质膜是新型生物传感平台的优秀候选者，因为它们的结构类似于细胞膜，并且相对容易修改膜的组成。对于这个目的，自支撑结构是优选的，因为膜蛋白的再构成更容易管理。因此，大多数用于生物传感的脂质膜基于固定在固体基底上的二维结构（与浮动脂质体不同），尽管它们存在一些缺点，例如低稳定性、小表面积和膜中潜在的溶剂保留。在本文中，在没有任何有毒溶剂的情况下，在 SU-8 微井中均匀地制造了三维自由站立脂质双层 (3D FLB) 阵列。由于其类似细胞的结构，3D FLB 具有更好的稳定性和更大的表面积。为了提高 3D FLB 的密封特性，在电形成过程中控制交流场的施加频率。通过共聚焦显微镜观察透明 SU-8 微井阵列中的 3D FLB，并在电形成后超过 1 kHz 时证明了完美的密封，直到 5.5 天。此外，首次讨论了固定的 3D 自由站立脂质结构的密封细节。通过转运蛋白（α-溶血素）测定验证了 3D FLB 的单分子层和生物功能。
