Carbon Nanotube-Based Chemiresistive Sensors

Abstract

The development of simple and low-cost chemical sensors is critically important for improving human life. Many types of chemical sensors have been developed. Among them, the chemiresistive sensors receive particular attention because of their simple structure, the ease of high precise measurement and the low cost. This review mainly focuses on carbon nanotube (CNT)-based chemiresistive sensors. We first describe the properties of CNTs and the structure of CNT chemiresistive sensors. Next, the sensing mechanism and the performance parameters of the sensors are discussed. Then, we detail the status of the CNT chemiresistive sensors for detection of different analytes. Lastly, we put forward the remaining challenges for CNT chemiresistive sensors and outlook the possible opportunity for CNT chemiresistive sensors in the future.

Keywords: carbon nanotubes; chemiresistive; functionalization; sensors.

Figure 1

Schematics of an individual (A) SWCNT and (B) MWCNT. Cited from Reference [9] with permission.

Figure 2

Schematic of configurations of CNT chemiresistive sensor.

Figure 3

Selected performance parameters of a device which is exposed to a rising concentration of analytes. Cited from Reference [24] with permission.

Figure 4

Three ways that analytes change the conductance of CNTs. (a) SWNT-electrode junction; (b) charge transfer among the SWNT and analytes; (c) intertube junction. Cited from [24].

Figure 5

Interaction of SWNT-PABS with NH₃. Adapted from Reference [53].