Noncovalent functionalization of solid-state nanopores via self-assembly of amphipols

Publication year: 2016
Authors: Pérez-Mitta G. 1, Burr L. 2, Tuninetti J.S. 1, Trautmann C. 2, Toimil-Molares M.E. 3, Azzaroni O. 4
Affiliations:

1 - Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, CC 16 Suc. 4 (1900) La Plata, Argentina

2 - GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany and Materialwissenschaft, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt, Germany

3 - GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany

4 - Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, CC 16 Suc. 4 (1900) La Plata, Argentina

Published in: Nanoscale, 2016, Vol. 8(3), p. 1470-8
doi: 10.1039/c5nr08190d

In recent years there has been increasing interest in the development of new methods for conferring functional features to nanopore-based fluidic devices. In this work, we describe for the first time the noncovalent integration of amphoteric-amphipathic polymers, also known as "amphipols", into single conical nanopores in order to obtain signal-responsive chemical nanodevices. Highly-tapered conical nanopores were fabricated by single-sided chemical etching of polycarbonate foils. After etching, the surface of the conical nanopores was chemically modified, by first metallizing the surface via gold sputtering and then by amphiphilic self-assembly of the amphipol. The net charge of adsorbed amphipols was regulated via pH changes under the environmental conditions. The pH-dependent chemical equilibrium of the weak acidic and basic monomers facilitates the regulation of the ionic transport through the nanopore by adjusting the pH of the electrolyte solution. Our results demonstrate that functional amphipathic polymers are powerful building blocks for the surface modification of nanopores and might ultimately pave the way to a new means of integrating functional and/or responsive units within nanofluidic structures.


MP-SPR keywords: amphipols, layer thickness, polymer, surface coverage, surfactant