Preparation and Enantiospecific Binding of Chiral Polyelectrolyte Multilayers: An In-Situ ATR-FTIR Study

Summary: Two chiral polyelectrolyte multilayers (PEM) composed of poly(L-lysine) (PLL) and poly(vinylsulfate) (PVS) as well as poly(ethyleneimine-maltose) (PEI-m) and poly(vinylsulfate) and a nonchiral PEM composed of poly(ethyleneimine) (PEI) and poly(vinylsulfate) were deposited on a silica surface using the layer by layer method. For both PEM enantiospecific interaction towards one enantiomer of either L-/D- glutamic acid (L-/D-GLU) or L-/D-ascorbic acid (L-/D-ASC), respectively, was checked under variation of the concentration. Both deposition and enantiospecific interaction were studied by attenuated total reflection Fourier transform (ATR-FTIR) spectroscopy. Preliminary results show a significant enantiospecific preference of D- GLU over L-GLU at PEM of PLL/PVS and of D-ASC over L-ASC at PEM of PEI-m/PVS and no such preference for nonchiral PEM of PEI/PVS. PEM of PLL/PVS shows higher enantiospecifity with increasing L-/D-GLU concentration.