Fabrication of a Single Metal Nanowire Connected with Dissimilar Metal Electrodes and Its Application to Chemical Sensing

Abstract

We report a convenient method for the fabrication of a single metal nanowire connected with dissimilar metal electrodes and its application to chemical sensing. The method is based on a combination of atomic force microscopy nanomachining and conventional photolithography. The success of this integrated approach is confirmed by the linear current-voltage behavior of the created nanowires and comparable resistivities with those reported previously. The chemical sensing capability is demonstrated by the selective binding of a self-assembled monolayer onto a single Au nanowire connected with Ti electrodes and the subsequent resistance increase due to increased surface scattering effects after adsorption. It is found that the resistance increases by around 9% after the complete coverage of either octadecanethiol or dodecanethiol molecules onto a 20 nm thick Au nanowire. A theoretical explanation for the relationship between the resistance increase and the alkanethiol concentration is also given.

Localized Surface Plasmon Resonance in Lithographically Fabricated Single Gold Nanowires

“…35 Another test for the chemical sensing capability was also conducted by measuring the peak wavelength changes due to the selective binding of an alkanethiolate self-assembled monolayer onto a Au NW. 36 A Au NW was immersed in a 20 mM octadecanethiol solution for 30 min and dried in air. A full coverage of the molecules on the NW was achieved.…”

“…A full coverage of the molecules on the NW was achieved. 36 The scattering spectra of the Au NW before and after the binding of the octadecanethiol molecules are shown in Figure 7b. The red peak shifts from 628 to 631 nm and the blue one from 489 to 491 nm.…”

NO gas sensing at room temperature using single titanium oxide nanodot sensors created by atomic force microscopy nanolithography

“…Au contact electrodes were subsequently created on the sides of the NW by standard photolithography. The details can be found in our previous reports [ 33 – 34 ]. For nano-oxidation, the tip was moved to the middle of the NW and a voltage pulse (−10 V and 500 ms) was applied to the tip.…”

Fabrication of single titanium oxide nanodot ultraviolet sensors by atomic force microscopy nanolithography

“…A standard photolithographic process was applied to produce Au electrodes. Details can be found in our previous reports [16,17]. The morphologies of the Ti NW and Au electrodes were examined by a field emission scanning electron microscope (SEM) (JSM 6500F, JEOL, Japan).…”

“…scanning probe lithography [13], are also feasible. Titanium oxide NW gas sensors fabricated by atomic force microscopy (AFM) nano-oxidation [14,15] and single Au NW chemical sensors fabricated by AFM nanomachining [16] have been reported. In this work, we demonstrate the fabrication of single titanium oxide nanodot (ND) UV sensors by a combination of AFM nanomachining, photolithography, and AFM nano-oxidation.…”