Covalent attachment of chiral alkaloids onto silicon surfaces

In this work, we report the covalent attachment of a chiral molecule onto a hydrogen-terminated Si(Si–H) surface by using an extremely mild approach. Cinchonine, a chiral alkaloid was self-assembled onto a Si–H surface via a photochemistry method at room temperature. The self-assembled monolayers (SAMs) obtained were characterized by means of ellipsometry, XPS and wettability studies. The film formation kinetics was monitored by ellipsometry and XPS, which indicated that a full monolayer was formed within 15 h. Contact angle titration data revealed that the surface of cinchonine underwent a transition around pH 10.