Metal-catalysed, bridging nanowires as vapour sensors and concept for their use in a sensor system

Abstract

Metal-catalysed silicon nanowires were grown between silicon electrodes and exposed to vapours containing HCl or NH3 at reduced pressure. Charge from adsorbed vapour modulated the conductance of the nanowires by changing the number of mobile carriers. Exposing the nanowires to HCl vapour increased the conductance while exposure to NH3 vapour decreased the conductance. The observed results suggest the use of an array of nanowire sensors integrated with silicon electronics. Preliminary area estimates indicate that integrated amplification and signal processing is feasible for an array of 1000 sensors.

Progress Toward Nanowire Device Assembly Technology

“…The trench is etched into the SOI until reaching the buried insulator layer. By using Si bridging nanowires grown on an SOI wafer, the HP group has realized a gas sensor and proposed a concept for using bridging nanowires to build a sensor system (Kamins et al, 2006). A typical process for the fabrication of Si bridging nanowires on an SOI is as follows.…”

Low-Dimensional Group III-V Compound Semiconductor Structures

“…Another feature contributing to various complications involved in the growth of nanowires is the presence of metal catalysts (e.g., metal-catalyzed nanowire growth with the presence of transition metal or noble metal particles). 102,103,104 Catalyst-free nanowire growths were also suggested, 105,106,107 however the level of complexities that would have to be handled in analyzing the growth of nanowires without metal-catalysts appears to be even much higher than that in metal-catalyzed nanowire growths. Therefore, the discussion on the role played by single-crystal substrates in the growth of nanowires, with or without metal catalysts, appears to be still in its infancy.…”

Recent advances in fiber-optic DNA biosensors

“…Nanoparticles [14,15], nanotubes [16,17], nanowires [17,18,19,20,21,22,23] and fiber-optics as the matrices of DNA biosensors to detect DNA specific sequence and DNA hybridization have been reported. Fiber opticbased DNA biosensors have many advantages over other matrices-based DNA biosensors as following: 1) Fibers have a flexible geometry and can be tractably miniaturized at low cost to nanosacle structure for in vivo measurements.…”