NER: Selective Growth of Nanoparticles at Exposed Carbon Nanotube Tips

California Institute Of Technology, Pasadena CA

Investigators

Abstract

NER-Proposal #0508096: Abstract The objective of this research is to grow nanoparticles directly on carbon nanotube tips for improved nanoelectrodes and novel self-assembly strategies. The approach consists in coating individual carbon nanotubes with a chemically inert sheath, then exposing the nanotube tip. Selective growth of a particle at the tip will follow utilizing gaseous precursors with enhanced reactivity towards carbon. The intimate tube-particle contact allows the particle to be used for sensing at the nanoscale when the nanotube is integrated on a scanning probe. The particle offers a larger area for the attachment of functional "sensing" molecules to increase sensitivity and allows chemistries, other than carbon-based, to be explored for anchoring. Functionalized nanoelectrodes can trigger and probe signaling pathways in cells or in electrophysiological fluids. Massive fabrication of nanotube-nanoparticle half-dumbbells bears promise for self-assembly at the nanoscale utilizing magnetic and/or hydrophobic-hydrophilic interactions. Such assemblies may lead to new functionalities and materials properties. The broader impact of the proposed research emerges from the ability to image and manipulate matter at the nanoscale. Nanoelectrodes can help improve understanding of signaling in biosystems ultimately connected with life and health. More sensitive nanoelectrodes can help detect more efficiently minute amounts of toxic or polluting chemicals of environmental importance. Nanotube-nanoparticle dumbbells will provide new building blocks for assembling new materials with improved structural, magnetic, electronic, and photonic properties. Nanotubes coupled to silicon quantum dots may increase the efficiency of solar energy conversion. Finally, nanotube-nanoparticle probes offer a new tool for exploring nanoscale systems.