Nanostructured ZnO surfaces as effective support for patterned biomolecules

ZnO nanostructured surfaces, fabricated via a versatile integration of metal organic chemical vapour deposition, chemical bath deposition and colloidal lithography represent suitable supports for patterned biomolecule adlayers. Such hybrid inorganic-organic materials constitute a benchmark in studying cell surface processes and provide an analytical platform for biosensing. A multi-technique approach has been used to characterize the chemical and physico-chemical properties of the ZnO nanostructured support at the interface with the biosystems. In particular, by using fluorescence recovery after photobleaching, we have followed differences in the lateral diffusion of the adsorbed biomolecules and investigated whether the fraction of mobile molecules is tunable by morphological (as evidenced by scanning electron microscopy and atomic force microscopy) and/or chemical surface properties (as studied by X-rays photoelectron spectroscopy, water contact angle). Evidences of laterally confined differences in adlayer mobility, triggered upon varying surface roughness through appropriate modulation of ZnO deposition process parameters, prove the effectiveness of such nanostructured platforms as promising support to selectively control the diffusion of adsorbed biomolecules.