Nanomaterial-based potentiometric sensors for neutral
species
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