| AVS 55th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Tuesday Sessions |
| Session NS+NC-TuA |
| Session: | Nanowires and Nanosize Effects |
| Presenter: | J.-W. Park, University of Utah |
| Authors: | J.-W. Park, University of Utah R. Sardar, University of Utah J.S. Shumaker-Parry, University of Utah |
| Correspondent: | Click to Email |
We have developed a simple, inexpensive, versatile asymmetric surface functionalization approach for controlled assembly of gold and silver nanoparticles. The process is based on spatially localizing ligands on the nanoparticle surface and uses commercially available organic reagents. The localization of the ligands allows for controlled assembly and we are able to control interpaticle spacing using different types of linkers. We have used this approach to prepare dimers using an amide coupling reaction between localized ligands on two asymmetrically functionalized nanoparticles. In addition, we demonstrate the synthesis of dimers consisting of particles with different sizes. Without optimization, the dimer yield varies from ~30% to ~65% depending on the nanoparticle sizes. The dimers demonstrate remarkable stability in ethanol without further processing. We also can combine the asymmetrically functionalized nanoparticles with other materials such as polymers for additional organization. For example, we have covalently linked asymmetrically functionalized gold nanoparticles to polymer pendent groups to form one-dimensional nanoparticle chains. The lengths of the nanoparticle chains vary from 256 to 400 nm with regular interparticle spacing (2.7-5.4 nm) within the chains. The chains display distinct optical properties compared to individual nanoparticles. The dimers and chain assemblies are being investigated as tunable optical platforms for surface-enhanced Raman spectroscopy.