Ferroelectric-specific peptides as building blocks for bio-inorganic devices

The integration of biomolecules with inorganic materials to create functional composites represents a critical step in the development of next-generation biosensors, micro/nanofluidic devices, and biochips that require a combination of abiotic (inorganics) and biotic (proteins, DNA, antibodies) components. Toward this end, we have previously applied combinatorial phage display techniques to identify a constrained heptapeptide sequence (CISLLHSTC) that selectively binds to a perovskite ferroelectric (MOCVD-deposited lead zirconium titanate, PZT). In this work, we examine the binding of this heptapeptide sequence, prepared by solid phase peptide synthesis to sol-gel PZT. In particular, the surface roughness has been examined and the. long-term stability of the PZT films in biological buffered aqueous solutions by atomic force microscopy, X-ray diffraction and P-E hysteresis loop. In addition, the selectivity of the peptide binding to PZT has been determined by immunofluorescence microscopy and the nature of peptide binding to the PZT surface is probed by X-ray photoemission spectroscopy.