We synthesized an anodic aluminum oxide nanostructure with a pore diameter of 80 nm (AAO80) directly
on a quartz crystal substrate and deposited a thin gold film onto the AAO80 (Au/AAO80). The nanostructure
surfaces were rendered hydrophobic via different chemical modifications to yield partially or fully
superhydrophobic surfaces; only the top gold surface was hydrophobic (T-Au/AAO), or both the gold
and AAO surfaces were hydrophobic (TS-Au/AAO). The surface wetting properties of each nanostructuregrown
quartz substrate immersed in water were investigated using a novel integrated system consisting
of a fiber optic spectrometer and a quartz crystal microresonator (QCM). A QCM was used to measure
the changes in the dissipation factor and the resonance frequency during surface wetting. A fiber optic
UV–vis spectrometer was used to measure the changes in the wavelength and peak intensities of the
interference fringes. Synchronous QCM and spectrometer measurements permitted in situ discrimination
between the permeation of water into the nanopores and the replacement of air interlayer with
water for the first time to the best of our knowledge.