Fabrication of ultra-sensitive piperidine chemical sensor with a direct grown well-aligned ZnO nanorods on FTO substrate as a working electrode

In this work, we report a direct growth of well-aligned zinc oxide nanorods (ZNRs) on fluorine doped tin oxide (FTO) substrate by a single step chemical method in an aqueous solution; the synthesized ZNRs were then used for piperidine sensing studies, as a working electrode. The ZNRs were uniformly grown in a large area, highly crystalline, and vertically aligned with an average length and diameter of ~650 nm and ~50 nm, respectively. The vertically aligned ZNRs provide the higher surface area for electrocatalytic activity of piperidine, and thus exhibited an ultra-sensitivity of 527 μAmM⁻¹cm⁻², a low detection limit (~60 nM), and a wide linear detection range from 0.1 μM to 200 μM. The improved piperidine sensing response characteristics of direct grown ZNRs on FTO substrate due to the large surface area, higher electrocatalytic activity and the fast electron transfer process, which makes them interesting candidate for fabricating other chemical sensing devices.