Ligand coated nanoparticles are assemblies consisting of an inorganic core protected by a self-assembled monolayer, often composed of a mixture of different molecules that together determine a large fraction of the particles' properties. Recently, using scanning tunneling microscopy, the presence of concentric ribbon-like domains of alternating composition when the ligand shell of gold nanoparticles is composed of phase-separated mixture of thiolated molecules has been shown. Significant properties, such as solubility or resistance to protein nonspecific adsorption, were found to depend on this arrangement. A series of studies to construct a set of ripple-structure/nanoparticle-property relationships are proposed. The goal is to contribute to the understanding of the interactions that happen between bio-molecules, such as viruses or protein globules, that also show nanometer scale domains on their outside 'shell'. Furthermore, we propose to create chains of 'divalent' nanoparticles to find the similarities and the differences that these nanoscale equivalents to polymers have with their molecular counterparts. The proposed work will naturally be integrated with undergraduate education efforts, for example by creating an open web version of his "Nanoscale Materials" class, and by creating two new laboratory experiments in the "Materials Laboratory" class.
Cells are molecular assemblies kept in nanometer-scale spatial arrangements by supramolecular interactions. Also, biomolecules, such as viruses or protein globules, have nanometer-scale assemblies of molecules on their outside. Recently, it has been observed that a synthetic material (ligand coated metal nanoparticles) shows a supramolecular arrangement on its outside shell that resembles, in size and composition, that present on biomolecules. It is proposed that these similarities be studied to try to understand what properties these types of arrangements determine. The goal is to contribute to the understanding of the interactions that biomolecules have among themselves and with the outside molecular world. The proposed work will be undertaken with the simultaneous training of a graduate student and many undergraduate students. In particular every year two summer undergraduate students will be hired from a local community college (Roxbury Community College) in order to expose young students from underrepresented minorities to the vibrant research environment at MIT. The proposed work will be an integral part of the P.I.'s undergraduate education efforts, for example by creating an open web version of the "Nanoscale Materials" class as well as two new laboratory experiments in the "Materials Laboratory" class.
