Two-Components Colloidal Solutions: Tuning the Interactions of Functionalized Nanoparticles with Proteins

• Applicant: Professor Dr. Frank Schreiber
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 123578767

Nanoparticles (NPs) functionalized by self-assembled monolayers (SAMs) and proteins (known as bioconjugates) are widely used in many bio-related areas, such as biomolecular detection and diagnostic applications. From the point of view of colloidal physics, understanding the phase behavior of these two-component (NPs plus proteins) systems is a challenge, especially given the non-trivial pair-wise interactions and their different response to environmental parameters. In this proposal, we will address the questions: What is the conformation/structure of specific SAM-forming molecules on NPs, and of adsorbed proteins at SAM-solvent interfaces? How do these affect the interactions and phase behavior of colloidprotein solutions? How do proteins interact with themselves as well as with functionalized NPs in solution? What are the key parameters determining the phase behavior of this two-component system (nature and concentration of salt, pH, T, …)? In order to study the interactions and phase behavior of protein-colloid mixtures in general, several typical proteins, specifically albumin, enzymes and antibodies will be used as those proteins are used exhaustively in biosensors. A set of complementary experimental techniques including small-angle scattering (SAXS, SANS), dynamic light scattering (DLS), and spectroscopy (FTIR, UV-vis and circular dichroism) will be used to address the different issues in these complex systems.

• DFG Programme: Research Grants
• Participating Person: Privatdozent Dr. Fajun Zhang, Ph.D.