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

GONZALO PÉREZ MITTA; LOÏC BURR; JIMENA S. TUNINETTI; CHRISTINA TRAUTMANN; MARÍA EUGENIA TOIMIL-MOLARES; OMAR AZZARONI

Nanoscale

RSC

Año: 2015

2040-3372

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