Sensor label with polyaniline-metal composites for meat freshness monitoring

In this study, ion-track membranes with pore diameters of 2 ± 0.1 μm and a fluence of 107 cm−2, with a thin layer of gold sputtered on one side, were used for the electrochemical synthesis of thin films from a polyaniline (PANI) composite with gold (Au) or silver (Ag) nanoparticles. PET (polyethylene terephthalate ion-track membranes) films with the thin film of TM+PANI/Au and TM+PANI/Ag composites, featuring a developed microstructured surface, were designed. Using ATR-FTIR (Attenuated Total Reflection – Fourier-transform infrared spectroscopy) and Raman spectroscopy, it was determined that PANI was synthesised predominantly in the form of an emeraldine salt, with a minor presence of the emeraldine base form. The TM+PANI/Au and TM+PANI/Ag films exhibited high sensitivity to ammonia, with detection thresholds of approximately 40 mg/L and 20 mg/L, respectively.