Functionalization of atomic force microscope tips by dielectrophoretic assembly of Gd(2)O(3):Eu(3+) nanorods.

An atomic force microscopy (AFM) tip has been coated with photoluminescent Eu(3+)-doped Gd(2)O(3) nanorods using a dielectrophoresis technique, which preserves the red emission of the nanorods (quantum yield 0.47). The performance of the modified tips has been tested by using them for regular topography imaging in tapping and contact modes. Both a regular AFM standard grid and a patterned surface (of an organic-inorganic methacrylate Zr-based oxo-cluster and poly(oxyethylene)/siloxane hybrid) have been used. Similar depth values have been measured using a conventional silicon tip and the nanorod-modified tip. The tips before and after use exhibit similar SEM images and photoluminescence spectra and, thus, seem to be stable under working conditions. These tips should find applications in scanning near-field optical microscopy and other scanning techniques.