Deep UV lithography on poly-L-lysine thin films was used to generate microarrays with enhanced hydrophilicity. This was manifested as adsorption of ambient humidity from air by areas exposed to UV fluence around 5 J/cm(2) and was made visible by phase-contrast microscopy. Kinetics of adsorption was investigated by a novel technique involving fabrication of submicrometer hydrophilicity grating by two-beam UV interferometry. In an aqueous colloidal medium, gold and polystyrene microspheres preferentially attach to areas that are relatively less hydrophilic, i.e., those areas not exposed to UV light. This observation provides a method for fabricating micro- and nanoporous arrays with controlled porosity. The technique is demonstrated with microspheres of sizes between 250 nrn and 10 mu m. (c) 2006 Elsevier Inc. All rights reserved.