SWCNTs are regarded as an excellent charge-transducing material, due to their special structure with p electrons on the side walls and the large surface area/volume ratio. The change in electrical characteristics of SWCNTs makes them suitable for potentiometric detection. For example, Rius et al. [75] used SWCNTs as a receptor layer to develop a potentiometric sensor for detecting neutral aromatic hydrocarbon in aqueous solutions with low ionic strength.
The sensing mechanism is that the adsorption of aromatic hydrocarbons onto the side walls of the CNTs through hydrophobic and p-p stacking interactions could lead to the change of the interfacial double-layer capacitance between the CNTs and the sample solution and subsequently influence the potential response