Interference‐Free Electrochemical Detection of Nanomolar Dopamine Using Doped Polypyrrole and Silver Nanoparticles

This paper presents a new approach to detect dopamine in nanomolar range using an electrochemical sensor utilizing a composite made of chitosan‐stabilized silver nanoparticles and p‐toluene sulfonic acid‐doped ultrathin polypyrrole film. Studies included cyclic voltammogram, amperometry, differential pulse voltammetry and also investigation by electrochemical impedance spectroscopy. A detection limit of 0.58 nM was achieved in the linear range 1×10−9 M to 1.2×10−7 M. High sensitivity towards DA, good reproducibility and long‐term stability have been demonstrated without interference from ascorbic acid, uric acid, epinephrine, L‐dopa, glucose. The sensing system was successfully applied for quantitative determination of dopamine in commercially available human blood serum.