A versatile approach based on nanosphere lithography is proposed to generate surface‐imprinted polymers for selective protein recognition. A layer of 750 nm diameter latex bead‐protein conjugate is deposited onto the surface of gold‐coated quartz crystals followed by the electrosynthesis of a poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) film with thicknesses on the order of the bead radius. The removal of the polymer bead‐protein conjugates, facilitated by using a cleavable protein‐nanosphere linkage is shown to result in 2D arrays of periodic complementary size cavities. Here it is demonstrated by nanogravimetric measurements that the imprinting proceeds further at molecular level and the protein (avidin) coating of the beads generates selective recognition sites for avidin on the surface of the PEDOT/PSS film. The binding capacity of such surface‐imprinted polymer films is ca. 6.5 times higher than that of films imprinted with unmodified beads. They also exhibit excellent selectivity against analogues of avidin, i.e., extravidin, streptavidin, and neutravidin, the latter being in fact undetectable. This methodology, if coupled with properly oriented conjugation of the macromolecular template to the nanoparticles, offers the possibility of site‐directed imprinting.

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Nanosphere lithography with nanosphere‐protein conjugates is proposed by R. E. Gyurcsányi and co‐workers as a generic method to create surface molecularly imprinted polymer films for selective protein recognition. , electrosynthesis of a polymer film in the voids of the nanosphere array followed by removal of the nanospheres generates complementary cavities bearing the imprints of the proteins.

Molecularly imprinted polymers bind their target compounds at binding sites. The binding sites are typically based on some type of functional group, such as carboxyl group. The total amount of such functional groups and their distribution into available and unavailable groups is not well known. The total binding capacity is usually indirectly determined from adsorption isotherms, which are measured much below the theoretical binding capacity. This work shows that in a variety of differently prepared, methacrylic acid based molecularly imprinted and nonimprinted polymers, all carboxylic groups used for the polymer synthesis are retained in the polymer, 80-90% of them can be accessed by strong bases and essentially the same amount can be used for adsorption of weak bases. This high level of adsorption can only be achieved, however, if the adsorbed weak base is strong enough, if the polymer is sufficiently elastic and if the solvent does not compete too strongly for the binding sites. These results may explain why the maximum binding capacities obtained from isotherm measurements are usually not equal to the total amount of available binding sites. This study confirms the usefulness of nonimprinted polymers at high loadings.