Biotemplated Archaella Nanoswimmers

Abstract In this work, archaella of the halophilic archaeon Halobacterium salinarum are implemented as biotemplates to fabricate nanoscale cargo delivery vehicles capable of precise magnetic actuation in low-Reynolds number fluids. Mesoporous silica is deposited onto the surface of archaella using a sol-gel method to thicknesses between 400 and 900 nm, creating a porous bioinert nanostructure. Following deposition of a thin film of nickel, swimming dynamics were investigated, and a maximum average swimming velocity of a few microns per second was achieved using a low-strength uniform rotating magnetic field. The nanoswimmers are shown to efficiently navigate low-Reynolds number fluids under open loop control. This approach establishes extremophile-derived biological architectures as versatile templates for the synthesis of functional nanoscale materials and provides a facile, cost-effective method for fabrication of controllable nanoswimmers, expanding biotemplating beyond conventional bacterial systems.