Ouyang W, Müller M, Appelhans D, Voit B. In situ ATR-FTIR investigation on the preparation and enantiospecificity of chiral polyelectrolyte multilayers.
ACS APPLIED MATERIALS & INTERFACES 2009;
1:2878-2885. [PMID:
20356170 DOI:
10.1021/am900597c]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Chiral polyelectrolyte multilayers (PEMs) consisting of poly(l-lysine) (PLL), poly(N-(S)alkylated 4-vinylpyridinium iodide), or poly(ethyleneimine maltose) (PEI-m) as polycations and poly(styrenesulfonic acid) sodium salt (PSS) or poly(vinyl sulfate) as polyanions, as well as a nonchiral PEM composed of poly(ethyleneimine) (PEI) and PSS were deposited on silicon substrates and poly(tetrafluoroethylene) membranes using the layer-by-layer method. For these PEMs, enantiospecific interaction toward one enantiomer of either l/d-glutamic acid (l/d-GLU), l/d-tryptophan, or l/d-ascorbic acid (l/d-ASC), respectively, was studied under variation of the concentration, pH, and ionic strength. Both deposition and enantiospecific interaction were analyzed by attenuated total reflection Fourier transform infrared spectroscopy. Our results show a significant enantiospecific preference of d-GLU over l-GLU at PEMs containing PLL and of d-ASC over l-ASC at PEMs containing PEI-m. No such enantiospecific preference was found for nonchiral PEMs containing PEI. The enantiospecificity of PEMs of PLL/PSS toward l/d-GLU could be significantly influenced by the ionic strength and pH values, so that increasing attractive electrostatic interactions resulted in higher enantiospecificity.
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