Patterning nanostructured, synthetic, polymeric receptors by simultaneous projection photolithography, nanomolding, and molecular imprinting

Microscope projection photolithography is combined with nanomolding and molecular imprinting for the fast microfabrication of molecularly imprinted polymer (MIP) arrays in the form of micrometric islands of nanofilaments. Dot diameters from 70-90 Îm are easily obtained using a 10× objective and a photomask carrying the desired pattern. The dots are composed of parallel nanofilaments of a high aspect ratio, 150 nm in diameter and several micrometers in length, which are obtained through a nanomolding procedure on porous alumina. The arrays are molecularly imprinted with the small molecule fluorescein or with the protein myoglobin. The fluorescein MIP arrays are able to specifically recognize their target, as demonstrated by fluorescence microscopy. A four-fold increase in binding capacity and imprinting factor (IF = 13) is obtained compared to non-nanostructured porous dots. Imprinting of the nanofilament arrays with the protein myoglobin as the template is also possible and allows for a high imprinting factor of 4.3. Such nanostructured microarrays of synthetic receptors obtained by projection photolithography have great potential in biosensor and biochip development. Fast microfabrication of molecularly imprinted polymer dot arrays can be achieved via microscope projection photolithography. When imprinted with fluorescein or with myoglobin, binding studies and fluorescence microscopy reveal that the fluorescence signal greatly increases for dots composed of polymer nanofilaments compared to plain dots. Such nanostructured microarrays of synthetic receptors have a great potential for biochips.