Electronic nose system based on polyaniline films sensor array with different dopants for discrimination of artificial aromas

- Sensors based on polyaniline films used to identify artificial aromas
- Sensors produced by in situ polymerization of PANI and doping with different acids
- HCl-doped PANI film showed best superficial regularity and smaller particles.
- Sensor HCl-doped exhibited highest and fastest response levels and best sensitivity.
- E-nose system was highly efficient in the differentiation the artificial aromas.

The aroma quality analysis in terms of sensory properties is important to the food industry. Chemical sensors based on polyaniline (PANI) films were produced and used in a sensors array (electronic nose) to distinguish three artificial aromas: strawberry, grape and apple. The sensors were produced by in situ PANI polymerization on interdigitated graphite electrodes and doped with different acids (hydrochloric acid - HCl, camphor sulfonic acid - CSA and dodecylbenzenesulfonic acid - DBSA). Morphological characterizations by field emission scanning electron microscope (FE-SEM) revealed the best superficial regularity with smaller and better distribution of particles to the HCl-doped PANI film, which exhibited highest and fastest response and best sensitivity. It was also demonstrated by principal component analysis (PCA) that the sensor array was highly efficient to distinguish artificial aromas, thereby being a promising tool for aroma quality analysis in various food industry sectors.

The graphical abstract shows the application of E-nose system for distinguishing artificial aromas (grape, strawberry and apple) using polyaniline sensing units made with different dopants: (HCl, CSA and DBSA). The results showed that the sensing units array has been appropriate on supplying variability to the E-nose system to establish a finger-printing for a given aroma within a global selectivity concept.58