Development of smart packaging from biodegradable polymers that allow monitoring food exposure conditions is important to reduce food and material packaging waste. The objective of this article is to evaluate the conductivity of polyaniline (PANI) in its doped form with dodecylbenzene sulfonic acid on morphological, structure, thermal, and electrical (Hall effect) properties of whey protein isolate (films. Films show immiscible with 10⁻³ S cm⁻¹ conductivity and semiconductor behavior due to a phase separation that is observed (scanning electron microscopy and thermogravimetric analysis). Fourier transform infrared and Raman spectra do not present changes in relation to control samples, suggesting no chemical interaction with polymers. This result is probably due to deprotonation of PANI. No significant differences are observed for conductivity of film made above 60 mg mL⁻¹ of PANI. Films showed semiconducting properties that allow a new application on smart packaging to help monitor electrical properties of foods in processes of degradable. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47316.