Generation of Solvent-Free 3D Lipid Structure Arrays on High Aspect Ratio Si Microwell Substrate

Abstract

Artificial lipid membranes are versatile platforms that are used extensively in biological assays and sensing applications. Particularly, a 2D bilayer lipid membrane (BLM) has been focused on over the last several decades as it can be formed easily on solid supports by various methods. However, 3D lipid structures with structural advantages, such as large surface area that can accommodate a number of proteins and steric conformation that can react with target molecules efficiently, for use as highly sensitive sensors rarely have been studied due to the technical limitations of sealing and stability. Herein, the growth mechanism and condition for the formation of a solvent-free, 3D lipid structure array (approximate to 300 000 ea cm(-2)) tightly bound on a microwell array by a gentle hydration method are investigated. Then, applying an electric field during rehydration step, 3D unilamellar structure array with high uniformity (coefficient of variation (CV): approximate to 4.9%) can be formed. A pore-forming protein assay (alpha-hemolysin) shows that the proposed structures are completely sealed and have biofunctionality that allows them to be used for fluorescent signal measurement, which is essential for biosensing applications. This approach is expected to be a promising first step toward the development of artificial biomimetic sensory organs that have high sensitivity.