Poly(3,4-ethylenedioxythiophene) (PEDOT) hollow microflowers and their application for nitrite sensing

A film of poly(3,4-ethylenedioxythiophene) hollow microflowers (PEDOT-HMF) was electrodeposited on a fluorine-doped tin oxide (FTO) glass substrate by using a film of ZnO microflowers as the template. Each of the PEDOT hollow microflowers shows several 2D nanopetals. Various charge densities were applied for the deposition of the PEDOT film, intending to investigate the charge effect on the filmʹs morphology. The FTO glass with the film of PEDOT-HMF (hereafter PEDOT-HMF modified electrode) was used as a nitrite sensor. A dramatic improvement was observed in the sensitivity of the PEDOT-HMF electrode, with reference to that of a flat PEDOT electrode. Through an amperometric detection, the sensitivity and limit of detection (LOD) of the sensor were found to be 255.2 μA mM−1 cm−2 and 0.59 μM, respectively. The linear range of the PEDOT-HMF electrode was between 50 and 7500 μM, and was observed to be larger than that of the corresponding PEDOT electrode. An interference effect was studied, using different kinds of salts that contain anionic interferences in the detection of nitrite. All the ions of the salts, except SO32−, showed negligible effect on the determination of nitrite.