GaN and InN nanocolumns as electrochemical sensing elements: Potentiometric response to KCl, pH and urea

GaN and InN nanocolumns have been explored as electrochemical sensing elements. It is shown that these nanostructured sensors respond to anions as their corresponding compact crystals, but with a much lower sensitivity (chloride anion detection). Moreover, even though both kinds of nanocolumns are found to be more vulnerable to HCl etching compared to their flat counterparts, they exhibit quite high pH sensitivity. This fact allows for their use as pH sensors only under mild conditions, such as in biosensing systems, as it is proved with the example of urea biosensors.