Well-defined sub-nanometer domains of organic molecules decorate a gold nanoparticle |
The ongoing development of nanotechnology is pushing the boundaries of science and engineering to new extremes. This is particularly true with the ultra-small bits of matter known as nanoparticles, which show great promise in a wide variety of applications ranging from biomedical to electronic. In a MRSEC funded seed project, Professor Stellacci has demonstrated that it is possible to create sub-nanometer ordered domains on these already remarkably tiny particles (see figure below). In this project (Jackson, et al, Nature Materials 3, 330-336, 2004) the authors have created a new family of nanoscale materials that present phase-separation at an unprecedented length scale. They show that when gold or silver nanoparticles are coated with a mixture of different ligands, ~6 Å wide alternating rings of hydrophobic and hydrophilic molecules form. This unique sub-nano-structuring of the ligand shell provides new properties to the particles such as unique and unexpected solubility that is controlled by the sub-nanometer texture. A remarkable resistance to protein nonspecific adsorption has also been observed, suggesting the use of these texture nanoparticles in biomedical devices and implants that require protein non-fouling properties.
