“Coulomb Staircase” at Room Temperature in a Self-Assembled Monolayer of Hydrophobic Fe/Pt@Au Core-Shell Nanoparticle

Abstract

Hydrophobic Fe/Pt@Au core-shell nanoparticles (NPs) were synthesized in a quaternary CTAB/n-butanol/n-heptane/water reverse micelle. Dodecylthiol coated around the NPs as functional agent could be help the NPs to form a self-assembled monolayer of which can be viewed clearly by transmission electron microscopy (TEM). A scanning tunneling microscope (STM) was used to find the subtle self-assembled monolayer of the NPs and to measure their current-voltage characteristics as a function of the separation between the probe tip and the self-assembled monolayer of hydrophobic Fe/Pt@Au core-shell NPs on graphite. At room temperature, when the tip was positioned over the monolayer NPs on graphite, the current-voltage data showed “Coulomb staircase” behavior.

Keywords:

• Coulomb staircase
• hydrophobic Fe/Pt@Au core-shell
• nanoparticles
• reverse micelle

Acknowledgements

This work was supported by the Foundation of Education Department in Hainan Province (Hjkj2009-13) and the National Natural Science Foundation of China (Grant No. 90207026).