화학공학소재연구정보센터
Langmuir, Vol.25, No.22, 13025-13033, 2009
Ionic Binding of Phosphotipids to Interfaces: Dependence on Metal Ion Identity
We report on the deposition of 1,2-(dimyristoyl-sn-glycero-3-phosphatidic acid (DMPA) on selected metalphosphate-terminated self assembled monolayers (SAMs) constructed on Au. The phosphate-terminated SAMs Were reacted with Zr4+, Cu+, Cu2+, Fe3+, Zn2+, Ni2+, Ca2+, and Mg2+, With subsequent exposure of the resulting interface to DMPA unilamellar vesicles. The resulting interface was characterized using X-ray photoelectron spectroscopy (XPS), optical ellipsometry, water contact angle measurements, and cyclic voltametry (CV). The strongest lipid-metal ion interfacial interactions are with Zr4+ and Fe3+ with Ca2+, Cu+, Ni2+, and Mg2+ producing somewhat less well organized adlayers. Cu2+ did not bind strongly to the interfacial phosphate moiety, yielding a lipid bilayer structure. These results call be understood in the context of the strength of the metal bisphosphate complex that forms between the phospholipid and the chemically modified interface.