The interphase degradation in a nanobiosensor including biopolymers and carbon nanotubes

[Display omitted] •The conductivity of PLA/PEO/CNT samples is analyzed to develop a nanobiosensor.•Simple model is developed to suggest the conductivity of samples by interphase degradation.•Degradation fraction, interphase depth and tunneling distance are considered in the model.•A thick interphase and a short tunneling distance increase the conductivity.•A thin interphase or a large tunnel induces an insulated nanocomposite. In this paper, a degradation nanobiosensor comprising two biopolymers as poly (lactic acid) (PLA) and poly (ethylene oxide) (PEO) as well as carbon nanotubes (CNT) is developed. The electrical conductivity of the samples for the period of degradation in phosphate-buffered saline (PBS) solution is analyzed focusing on interphase degradation. Furthermore, a model for the conductivity of examples is advanced by CNT properties, filler wettability by polymer medium, interphase depth, degradation portion and tunneling distance. The model’s calculations are linked to the experimental facts and all parameters’ impacts on the conductivity of the decayed examples are described. The predictions of the suggested model sufficiently follow the empirical data. The interphase thickness dwindles during degradation and a high content of CNT largely eliminates the polymer and interphase region, because CNT accelerate the degradation. Both thick interphase and short tunnels obtain the high conductivity, while either thin interphase or a large tunnel causes an insulated example, since thin interphase or a big tunnel prevents the electron transferring. This study can provide a simple approach to calculate and optimize the conductivity to predict the behavior of a degradation nanobiosensor.