title: Nanoporous elements in microfluidics for multiscale manipulation of bioparticles.
abstract: Solid materials, such as silicon, glass, and polymers, dominate as structural elements in microsystems including microfluidics. Porous elements have been limited to membranes sandwiched between microchannel layers or polymer monoliths. This paper reports the use of micropatterned carbon-nanotube forests confined inside microfluidic channels for mechanically and/or chemically capturing particles ranging over three orders of magnitude in size. Nanoparticles below the internanotube spacing (80 nm) of the forest can penetrate inside the forest and interact with the large surface area created by individual nanotubes. For larger particles (>80 nm), the ultrahigh porosity of the nanotube elements reduces the fluid boundary layer and enhances particle-structure interactions on the outer surface of the patterned nanoporous elements. Specific biomolecular recognition is demonstrated using cells (≈10 μm), bacteria (≈1 μm), and viral-sized particles (≈40 nm) using both effects. This technology can provide unprecedented control of bioseparation processes to access bioparticles of interest, opening new pathways for both research and point-of-care diagnostics.
authors.affiliation: BioMEMS Resource Center, Massachusetts General Hospital, 114 16th Street, Charlestown, MA 02139, USA.
authors.forename: Grace D
authors.initials: GD
authors.lastname: Chen
authors.forename: Fabio
authors.initials: F
authors.lastname: Fachin
authors.forename: Marta
authors.initials: M
authors.lastname: Fernandez-Suarez
authors.forename: Brian L
authors.initials: BL
authors.lastname: Wardle
authors.forename: Mehmet
authors.initials: M
authors.lastname: Toner
mesh_terms: D044085:Microfluidics / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010539:Permeability; D016062:Porosity