Do you by "charge" mean load some sensing material into the polymer? Then you may find some inspiration in the paper:

‘Stuffed’ conducting polymers, POLYMER 46(13):4664-4669  (2005).

If you refer to electrical charge, then over oxidized PPy is  poorly conducting, and it will be difficult to do something along these lines.

keld

If a  CV is carried out in neutral medium and found out the oxidation and reduction peak due to polypyrrole, then one can overoxidized the sample by holding that oxidation potential.

By charge I mean not to electropolymerize the layer of polymer but rather want to electrically charge and discharge the electropolymerized layer. I want to have a selective uptake of analyte into the imprinted cavity due to electrostatic interaction.

Electrochemically synthesized graphene/polypyrrole composites and their use in supercapacitor

Carbon Volume 50, Issue 6, May 2012, Pages 2331–2336

You can find some information in this work. A specific capacitances estimated from galvanostatic discharge curves in 1 M H2SO4 at a current density of 1 A g−1 indicated that values for the RGO/PPy composite were larger than those of a pristine PPy film and the GO/PPy composite. In the case of 6 mg mL−1 GO for the preparation of GO/PPy, a high specific capacitance of 424 F g−1 obtained at the electrochemically prepared RGO/PPy composite indicated its potential for use as an electrode material for supercapacitors.