Interaction of colloidal particles with biologically relevant complex surfaces

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 580; p. 123778
• Main Authors: Hernández-Meza, J. Manuel, Vélez-Cordero, J.R., Yáñez-Soto, Bernardo, Ramírez-Saito, A., Aranda-Espinoza, S., Arauz-Lara, J.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2019
• Subjects: Biophysics; Interaction-potentials; Soft-matter; Soft-matter; Interaction-potentials; Biophysics
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2019.123778

[Display omitted] The interaction of colloidal particles with functionalized glass surfaces is determined by tracking the settling of the particles towards such surfaces. The tracking is realized by optical microscopy, using the point spread function of fluorescent colloidal particles which allow us to follow the three-dimensional motion of the particles in a range of several micrometers above the surfaces. The surface/particle direct interaction is inferred from the distribution of particle's heights which also depends on the effective particle's weight and the thermal energy. The systems studied are aqueous suspensions of negatively charged 1 μm polystyrene beads diffusing above bare glass, glass coated with polyelectrolytes or glass coated with a phospholipid monolayer. Maximum anti-fouling properties were observed for the hyaluronate/particle and lipid/particle systems; on the other hand, a large number of particles were adsorbed on a passivated poly-l-lysine coating and bare glass. In addition, the gravitational term of the interaction potential revealed that the particles interacting with functionalized walls weighted more (beyond polydispersity limits) than particles interacting with bare glass. Molecule adsorption on the particle's surfaces as well as the functionalization quality were confirmed and characterized by additional particle's ζ-potential and AFM measurements.