ABSTRACT
In general, nanostructures with relatively small sizes constitute excellent signal transduction elements when dealing with biological analytes or chemical species. The reason for this is the similarity of the order of size between nanostructures and biological analytes and chemical species. The consequence of this issue is the fact that nanostructures will possess relatively very high sensitivity for detection of the biological analytes and chemical species compared to conventional large bulk sensors. In addition, sensors based on nanostructures can operate eficiently when the detection is for situations where the available sample volume is small and the concentration of the element of analyte in question is low. This is in fact a very important advantage of nanostructure-based sensors. Among the various known nanostructures, nanowires (NWs) and nanorods (NRs), with their relatively high-surface-area-to-volume ratio, constitute excellent signal transduction elements and have other advantages due to their geometrical features. On the other hand,
zinc oxide (ZnO), being biosafe and biocompatible, is an attractive material for implementation as an active sensor element. Moreover, among the different sensor procedures, the potentiometricbased procedure is one of the most attractive procedures for bioenvironments due to the fact that it is based on measuring charge accumulation with no current passing through the media.
