Biologically functionalized nanochannels on ferroelectric lead zirconium titanate surfaces

We have demonstrated the feasibility of selective functionalization of a ferroelectric thin film, allowing it to be used for the manipulation of charged biomolecules. This hybrid inorganic-biomolecular platform may find use in electrically actuated valves capable of controlling flow in nanochannels. The nanochannels are patterned on a ferroelectric lead zirconium titanate (PZT) thin film grown on a platinum electrode substrate. The channels are fabricated using a new bilayer resist method in order to create addressable encapsulated channels in one process step. A bacterial virus (bacteriophage) is used to identify ligands that selectively bind to the PZT surface. After attaching the biomolecules in specific locations along the channels, a voltage is applied to the PZT layer resulting in polarization of the surface, thus creating charges that cause the biomolecules to tether. Such tethering can be used like a valve in a nanofluidic channel. The biological valve discussed in this paper would enable many applications, including "lab-on-a-chip" and controlled medical drug delivery.