Nanosphere Lithography as a Versatile Method to Generate Surface‐Imprinted Polymer Films for Selective Protein Recognition

Abstract

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.

Electrosynthesized molecularly imprinted polymers for protein recognition

“…The precise control over electrosynthesis enables the fine tuning of the polymer layer thickness, which is particularly important for the surface imprinting of proteins. Electrosynthesis can be used straightforwardly to create several nanometer thick polymer films [52,53] and with the aid of sacrificial materials, micro and nanostructures with surface confined binding sites [5,[54][55][56]. It must be noted that beside direct electrooxidation of suitable monomers the versatility of electrochemical synthesis enables surface confined polymer deposition also by electrochemically generating the "active" initiator [57] or electrochemically changing the local pH in the close vicinity of the electrode [58].…”

“…The oriented protein imprinting can be achieved also by using an inert nanoparticle support for their immobilization [54,86] instead of the surface of an electrode. The approach introduced by the group of Gyurcsányi used such particles to create nanostructured polymer films by assembling polystyrene nanospheres into a monolayer on the surface of an electrode, electropolymerizing PEDOT-PSS film in the voids between the spheres and then dissolving the nanospheres (Fig.…”

“…This concept works best with conducting polymers alleviating the demand for ultrathin films while providing a higher binding capacity owing to the increased specific surface of the polymer. Most importantly, a significantly better discrimination could be achieved between avidin (used as target) and its analogues when the template was immobilized through its biotin-binding site [54], than with the same type of polymer imprinted with randomly immobilized avidin [56]. Template synthesis using polycarbonate-based sacrificial materials of Av-imprinted PEDOT-PSS microstructures in the form of surface confined microrods (A) (adapted with permission of ref.…”

Electronic Transport and Anisotropic Conductivity Behavior on PEDOT:PSS Nanoribbons and Nanostructuring Modification by Atomic Force Microscope Nanoshaving

“…Self-assembly methods, on the other hand, enable high fabrication output, but suffer from poor or limited control over feature size. Pervious nano, micro fabrication and lithography on poly (3,4-ethylenedioxythiophene) polystyrene sulfonate have demonstrated high-density arrays of organic semiconductors, showing a large throughput and high control of the features size [22][23][24][25]. On the other hand, self-assembly methods, enable high fabrication output, but suffer from poor or limited control over feature size.…”

Transcription-Type Protein Imprinted Polymers for SPR Sensing Prepared Using Target-immobilized Stamps based on Submicrometer-Sized Particles via Biotin-Avidin Linkage

“…The subsequent removal of the template molecule leaves the imprinted cavities complementary in size, shape, and interaction activity. Recently, many efforts have been made to prepare MIPs for proteins [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. However, MIPs prepared by the conventional bulk polymerization often contain incomplete cavities due to the buried template proteins, resulting in a more nonspecific binding and less accessibility.…”