Structure and Function of the Membrane Anchoring Self-Assembled Monolayers

Published

December 14, 2014

Author(s)

David J. Vanderah, Tadas Ragaliauskas, Mindaugas Mickevicius, Mariya Jankunec, Gediminas Niaura, Gintaras Valincius, Bozena Rakovska

Abstract

Structure of the self-assembled monolayers (SAMs) used to anchor phospholipid bilayers to surfaces affects the functional properties of the tethered bilayer membranes (tBLMs). SAMs of the same surface composition differing in the lateral distribution of the anchor molecule give rise to tBLMs of profoundly different defectiveness with residual conductance spanning 3 orders of magnitude. SAMs composed of anchors containing saturated alkyl chains, upon exposure to water (72 h), reconstruct to tightly packed clusters as deduced from reflection absorption infrared spectroscopy data and directly visualized by atomic force microscopy. The rearrangement into clusters results in an inability to establish highly insulating tBLMs on the same anchor layer. Unexpectedly we also found that nanometer scale smooth gold film surfaces, populated predominantly with (111) facets, exhibit poor performance from the standpoint of the defectiveness of the anchored phospholipid bilayers, while corrugated (110) dominant surfaces produced SAMs with superior tethering quality. Although the detailed mechanism of cluster formation remains to be clarified, it appears that smooth surfaces favor lateral translocation of the molecular anchors, resulting in changes in functional properties of the SAMs. This work unequivocally establishes that conditions that favor cluster formation of the anchoring molecules in tBLM formation must be identified and avoided for the functional use of tBLMs in biomedical and diagnostic applications.

Citation

Langmuir

Volume

31

Pub Type

Journals

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DOI Link

Keywords

Tethered bilayers, self-assembled monolayers, phospholipid membranes, clusters, electrochemical impedance spectroscopy, atomic force microscopy, electrochemistry, and surface structure.

Citation

Vanderah, D. , Ragaliauskas, T. , Mickevicius, M. , Jankunec, M. , Niaura, G. , Valincius, G. and Rakovska, B. (2014), Structure and Function of the Membrane Anchoring Self-Assembled Monolayers, Langmuir, [online], https://doi.org/10.1021/la503715b (Accessed April 25, 2024)