ZnO nano-platforms for fluorescence based biosensing

Fluorescence-based detection capability of ultrathin nanopatterned ZnO films, fabricated by using colloidal lithography and MOCVD at unusual low temperatures and short deposition times, which consist of circular SiO2 areas confined by ordered and dense array of ZnO nanorings, is herein investigated. Using a model analyte biomolecule (fluorescein-labeledalbumin) the newly prepared hybrid ZnO/SiO2 nano-structures, are proven effective to enhance the detection capability of biomolecular fluorescence. The interaction of ZnO/SiO2 hybrid nano-platforms with albumin has been studied by X-ray photoelectron spectroscopy and related optical emission changes investigated by laser scanning confocal microscopy. Fluorescence recovery after photobleaching measurements of the mobility of the protein at the biointerface between the biomolecule adlayer and ZnO substrates indicate that the lateral diffusion properties of the fluorescent molecules are related – then possibly triggered- by the tailoring of the chemical and/or topographical patterning of hybrid ZnO2/SiO2 surfaces.