Contactless electrofunctionalization of a single pore.

Customized pores are smart components that find challenging applications in a variety of fields including purification membranes and biosensing systems. The incorporation of recognition probes within pores is therefore a challenge, due to the technical difficulty of delimiting the area functionalized and obtaining the localized, specific chemical modification of pore walls. An innovative approach, named contactless electrofunctionalization (CLEF), is presented to overcome this problem. CLEF allows easy, one-step modification of the inner surface of a pore etched in a dielectric membrane. The pore wall is coated under the influence of an electric field created by the application of a voltage between two electrodes, located near but not in contact with the pore openings. This specific localization of the deposited material within the pore is extremely rapid. Coatings were reliably and reproducibly obtained using polypyrrole co-polymers bearing oligonucleotides, demonstrating that this technology has a promising future in the design of biosensors. Moreover, the versatility of this process allows the deposition of various electroactive entities such as iridium oxide and therefore indicates a strong potential for diverse applications involving porous materials.