Highly oriented, self-assembled alkanephosphate monolayers on tantalum(V) oxide surfaces

Octadecyl phosphoric acid ester has been found to produce oriented, well-or dered monolayers on a flat tantalum(V) oxide surface, via self-assembly fro m a heptane/propan-2-ol solution. By means of contact angle, optical wavegu ide lightmode spectroscopy (OWLS), near-edge X-ray absorption fine structur e spectroscopy (NEXAFS), and X-ray photoelectron spectroscopy (XPS) measure ments, it has been shown that these layers closely resemble those formed by the corresponding thiol-gold system, with respect to packing density, incl ination, and order. The system shows promise as an approach to functionaliz ing oxide surfaces with well-ordered organic monolayers, with potential app lications in the fields of biochemical analysis and sensors.