title: Ultrafast molecular motor driven nanoseparation and biosensing.
abstract: Portable biosensor systems would benefit from reduced dependency on external power supplies as well as from further miniaturization and increased detection rate. Systems built around self-propelled biological molecular motors and cytoskeletal filaments hold significant promise in these regards as they are built from nanoscale components that enable nanoseparation independent of fluidic pumping. Previously reported microtubule-kinesin based devices are slow, however, compared to several existing biosensor systems. Here we demonstrate that this speed limitation can be overcome by using the faster actomyosin motor system. Moreover, due to lower flexural rigidity of the actin filaments, smaller features can be achieved compared to microtubule-based systems, enabling further miniaturization. Using a device designed through optimization by Monte Carlo simulations, we demonstrate extensive myosin driven enrichment of actin filaments on a detector area of less than 10 μm², with a concentration half-time of approximately 40 s. We also show accumulation of model analyte (streptavidin at nanomolar concentration in nanoliter effective volume) detecting increased fluorescence intensity within seconds after initiation of motor-driven transportation from capture regions. We discuss further optimizations of the system and incorporation into a complete biosensing workflow.
authors.affiliation: The Nanometer Structure Consortium (nmC@LU), Division of Solid State Physics, Lund University, SE-22100 Lund, Sweden.
authors.forename: Mercy
authors.initials: M
authors.lastname: Lard
authors.forename: Lasse
authors.initials: L
authors.lastname: Ten Siethoff
authors.forename: Saroj
authors.initials: S
authors.lastname: Kumar
authors.forename: Malin
authors.initials: M
authors.lastname: Persson
authors.forename: Geertruy
authors.initials: G
authors.lastname: Te Kronnie
authors.forename: Heiner
authors.initials: H
authors.lastname: Linke
authors.forename: Alf
authors.initials: A
authors.lastname: Månsson
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D009010:Monte Carlo Method; D009038:Motion; D009218:Myosins / Q000378:metabolism*; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D011817:Rabbits; D019809:Streptavidin / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D019809:Streptavidin; D009218:Myosins