NU 2010-184

Inventors

Anne-Isabelle Henry

Mark Hersam*

Timothy Tyler

Richard Van Duyne*

Abstract

Northwestern researchers have developed an aqueous surfactant-free centrifugal sorting method for plasmonic nanoantennas. Relatively massive gold/silica nanoparticle clusters yields populations of predominantly one aggregation state and an enhanced ensemble surface-enhanced Raman spectroscopy (SERS) response. The microantennas are sorted by sedimentation coefficient via transient density gradient centrifugation and produces samples with a preponderance of a selected aggregation state. The silica shell not only allows the nanoparticles to be dispersed in water without further functionalization or surfactants but also protects the SERS reporter molecules at the gold/silica interface. This new technology improves control over nanparaticle cluster sizes and reliability and reproducibility in plasmonic applications such as SERS-based sensors. This sorting approach can be applied to a wide variety of core/shell nanoparticle structures in general to achieve more monodisperse samples for relatively large nanoparticles.

Applications

• Nanoparticles
• Drug Delivery
• Industrial Coatings
• Battery Anodes
• Solar Cells
• Core/Shell Nanoparticles
• Optical sensing
• MRI
• Fluorescence imaging
• Pigments
• Catalysis
• Plasmonic nanoantennas (security industry)

Advantages

• Higher detection signals
• Improved reliability and reproducibility between samples
• Improved population control over particles too massive for current centrifugal sorting techniques

Publication
Tyler TP, Henry AI, Van Duyne RP and Hersam MC (2011) Improved Monodispersity of Plasmonic Nanoantennas via Centrifugal Processing. The Journal of Physical Chemistry Letters. 2: 218-222.

IP Status

Issued US Patent No. 9,802,818.