Polyaniline-based cadaverine sensor through digital image colorimetry

The detection of biogenic amines is important due to the their correlation with spoilage and toxicity. Polyaniline (PANI) is a polymer capable of changing color from blue to green and vice versa through add-base reactions. This study tested the potential of PANI as a sensing material for the presence of cadaverine. PANI was fabricated on nylon cloths through the redox reaction of aniline and ammonium persulfate. The PANI-coated nylon cloths were exposed to different amounts of cadaverine in a fixed reaction time of 5 min. Through digital image colorimetry, plots of the different color values vs. concentration were prepared and the curve with the highest linearity was obtained using the yellow value. Values for limit of detection (LOD) and limit of quantification (LOQ) were calculated to be 0.8816 mm and 2.9386 mM, respectively. An Android application which analyzes the color values of the PANI image in relation to the amount of cadaverine was also developed.