Characterization of nanostructured surfaces generated by reconstitution of the porin MspA from Mycobacterium smegmatis.
Nanostructures with long-term stability at the surface of gold electrodes are generated by reconstituting the porin MspA from Mycobacterium smegmatis into a specially designed monolayer of long-chain lipid surfactant on gold. Tailored surface coverage of gold electrodes with long-chain surfactants is achieved by electrochemically assisted deposition of organic thiosulfates (Bunte salts). The subsequent reconstitution of the octameric-pore MspA is guided by its extraordinary self-assembling properties. Importantly, electrochemical reduction of copper(II) yields copper nanoparticles within the MspA nanopores. Electrochemical impedance spectroscopy, reflection electron microscopy, and atomic force microscopy (AFM) show that: 1) the MspA pores within the self-assembled monolayer (SAM) are monodisperse and electrochemically active, 2) MspA reconstitutes in SAMs and with a 10-nm thickness, 3) AFM is a suitable method to detect pores within SAMs, and 4) the electrochemical reduction of Cu2+ to Cu0 under overpotential conditions starts within the MspA pores.
Wörner
Michael
M
Department of Chemical and Process Engineering, University of Karlsruhe, 76128 Karlsruhe, Germany. michael.woerner@ciw.uni-karlsruhe.de
Lioubashevski
Oleg
O
Basel
Matthew T
MT
Niebler
Sandra
S
Gogritchiani
Eliso
E
Egner
Nicole
N
Heinz
Christian
C
Hoferer
Jürgen
J
Cipolloni
Michela
M
Janik
Katharine
K
Katz
Evgeny
E
Braun
Andre M
AM
Willner
Itamar
I
Niederweis
Michael
M
Bossmann
Stefan H
SH
D002462:Cell Membrane; D003300:Copper / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D004583:Electrons; D006046:Gold / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D018716:Molecular Mimicry; D050505:Mutant Proteins; D020102:Mycobacterium smegmatis / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D018272:Porins / Q000737:chemistry* / Q000648:ultrastructure; D016062:Porosity; D013501:Surface-Active Agents; D013885:Thiosulfates / Q000737:chemistry
D050505:Mutant Proteins; D018272:Porins; D013501:Surface-Active Agents; D013885:Thiosulfates; C121838:mspA protein, Mycobacterium smegmatis; D006046:Gold; D003300:Copper