Nanotube Molecular Wires as Chemical Sensors

TLDR

Single‑walled carbon nanotube sensors form the basis for nanotube molecular sensors. The study investigates the interactions between molecular species and SWNTs and the mechanisms of molecular sensing with nanotube molecular wires. Sensor reversibility is achieved by slow recovery under ambient conditions or by heating to high temperatures. Chemical sensors based on individual single‑walled carbon nanotubes were demonstrated, showing dramatic resistance changes to gases such as NO₂ or NH₃, fast response, and substantially higher sensitivity than existing solid‑state sensors at room temperature.

Abstract

Chemical sensors based on individual single-walled carbon nanotubes (SWNTs) are demonstrated. Upon exposure to gaseous molecules such as NO(2) or NH(3), the electrical resistance of a semiconducting SWNT is found to dramatically increase or decrease. This serves as the basis for nanotube molecular sensors. The nanotube sensors exhibit a fast response and a substantially higher sensitivity than that of existing solid-state sensors at room temperature. Sensor reversibility is achieved by slow recovery under ambient conditions or by heating to high temperatures. The interactions between molecular species and SWNTs and the mechanisms of molecular sensing with nanotube molecular wires are investigated.