Dear Margarita,

This not simple task as electrochemical activity of PANI depends on a lot of preconditions and electrolyte nature. But there are a lot of publication on the topic. E.g., for the beginning you can look at my old review Article Stability and degradation of conducting polymers in electroc...

I agree with Alexander above - the only thing to add is that if your analyte is also electroactive, it may actually undergo degradation before PANI does.

Frankly, more information about your system would help us provide you with a detailed answer. That said, you might want to consider an approach alternate to electro-degradingPANI.