Structuring of Organic Solvents at Solid Interfaces and Ramifications for Antimalarial Adsorption on β-Hematin Crystals

A critical aspect of material synthesis is solvent structuring at solid–liquid interfaces, which can impact the adsorption of solute and growth modifiers on an underlying substrate. In general, the impact of solvent structuring on molecular sorbate interactions with solid sorbents is poorly understood. This is particularly true for processes that occur in organic media, such as hematin crystallization, which is crucial to the survival of malaria parasites. Here, we use chemical force microscopy and molecular modeling to analyze the interactions between functional moieties of known antimalarials and the interface between β-hematin crystals and a mixed organic (octanol)–aqueous solvent. We show that the β-hematin surface, patterned in parallel hydrophobic and hydrophilic stripes, engenders the assembly of up to five layers of octanol molecules aligned parallel to the crystal surface. In contrast, studies of solvent structuring on a disordered glass surface reveal that octanol molecules align perpendicular t...