Discovery of Targeted Material Binding Microorganisms Using a Centrifugal Microfluidic Platform

Abstract Discovery of unique peptides that specifically bind to target materials of interest is commonly achieved through biopanning‐based screening of cell libraries having high diversity. However, conventional methods have limitations in the generation of controllable shear stress applied in order to effectively remove weak and unbound cells from a target material. Here, a centrifugal force‐based microfluidic biopanning platform is presented. Using this microfluidic platform, a wide range of shear stress conditions can be generated by simply adjusting the rotation speed of the platform, which provides a precisely controllable wash step. The enhanced circularly permuted outer membrane protein X (eCPX) 3.0 bacterial peptide display library (≈10¹¹ number of cells) is screened, and many isolates that show strong affinity towards gold only, ITO only, or both are successfully obtained through a multiround iterative sorting process. Amino acid contents of the resulting isolates are analyzed to provide a better understanding of the distinctive attributes of these peptides and their specific material‐binding capabilities. This platform is simple and easy to use and can be readily applied to screen microbial libraries against virtually any material surface of interest, which can greatly accelerate the discovery of peptide‐driven biomaterials and the development of hybrid organic–inorganic materials.