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Polydopamine Meets Solid-State Nanopores: A Bioinspired Integrative Surface Chemistry Approach To Tailor the Functional Properties of Nanofluidic Diodes
journal contribution
posted on 2015-05-13, 00:00 authored by Gonzalo Pérez-Mitta, Jimena S. Tuninetti, Wolfgang Knoll, Christina Trautmann, María Eugenia Toimil-Molares, Omar AzzaroniThe
ability to modulate the surface chemical characteristics of
solid-state nanopores is of great interest as it provides the means
to control the macroscopic response of nanofluidic devices. For instance,
controlling surface charge and polarity of the pore walls is one of
the most important applications of surface modification that is very
relevant to attain accurate control over the transport of ions through
the nanofluidic architecture. In this work, we describe a new integrative
chemical approach to fabricate nanofluidic diodes based on the self-polymerization
of dopamine (PDOPA) on asymmetric track-etched nanopores. Our results
demonstrate that PDOPA coating is not only a simple and effective
method to modify the inner surface of polymer nanopores fully compatible
with the fabrication of nanofluidic devices but also a versatile platform
for further integration of more complex molecules through different
covalent chemistries and self-assembly processes. We adjusted the
chemical modification strategy to obtain various configurations of
the pore surface: (i) PDOPA layer was used as primer, precursor, or
even responsive functional coating; (ii) PDOPA layer was used as a
platform for anchoring chemical functions via the Michael addition
reaction; and (iii) PDOPA was used as a reactive layer inducing the
metallization of the pore walls through the in situ reduction of metallic
precursors present in solution. We believe that the transversal concept
of integrative surface chemistry offered by polydopamine in combination
with the remarkable physical characteristics of asymmetric nanopores
constitutes a new framework to design multifunctional nanofluidic
devices employing soft chemistry-based nanofunctionalization techniques.