On-site monitoring of fish spoilage using vanadium pentoxide xerogel modified interdigitated gold electrodes

The development of a vanadium pentoxide xerogel (VXG)-based sensor for the detection of volatile inorganic (ammonia) and organic (dimethylamine, etc.) amines is described. The xerogel film was deposited on interdigitated gold electrodes by dip-coating using an aqueous solution of VXG. The morphology of the sensing layer, its interaction with ammonia, which was used as a model analyte throughout this work, as well as the regeneration of the surface of the sensor electrodes with vapors of HCl were examined with scanning electron microscopy and FTIR spectroscopy. Signal changes, due to changes of the RC-product of the electrochemical cell (Au-VXG-Au), as a result of its interactions with ammonia vapors, were probed with a portable, homemade charge meter, the Multipulser. Exposing the sensor electrodes to various concentrations of ammonia vapors resulted in proportional changes in the signal output. Finally, the proposed sensors were successfully used for on-site, real-time monitoring of fish spoilage in ambient conditions.