Tailored ZnO nanoplatforms as hybrid biosensor substrates for fluorescence based biosensing

Advanced biosensor targets for biomolecular fluorescence detection are characterized by multitasking capability, sensitivity and high specificity. Herein, a combined Metal-organic Chemical Vapour Deposition - Chemical Bath Deposition approach has been used to grow ZnO nanorods on unpatterned and patterned substrates. Structure and thickness of ZnO buffer layers (deposited by MOCVD) strongly influence the CBD growth rate and, consequently, the final morphology and crystal texturing of ZnO nanorods. Ordered two-dimensional arrays, obtained by colloidal lithography, have been proven effective to build up hybrid ZnO/SiO2 nanoplatforms in the perspective of development of advanced biosensor substrates. In fact, by laser scanning microscopy observations the great potential of such systems as innovative fluorescence sensing substrates, with individual addressability and tuning of the biomolecular detection capability has been demonstrated. Indeed, the green emission of the different hybrid ZnO nanostructures is significantly affected by the protein immobilization process. Moreover, the fluorescence recovery after photobleaching technique provides evidence that the protein mobility and fluorescence detection capability are tunable by proper patterning and morphological control of the hybrids ZnO based nanoplatforms.