In this study, pencil graphite electrode was modified using conductive polypyrrole (Ppy) and grapheme (GF) nanocomposite for electrochemical determination of insulin. Electrochemical behavior of insulin on PGE was investigated using cyclic voltammetric (CV) and differential pulse voltammetric (DPV) and chronoaprometry (CA) methods. Several effective parameters including pH, concentration, and s...