Selective sensing of dopamine by sodium cholate tailored polypyrrole-silver nanocomposite

Conducting polymer-noble metal nanocomposites have attracted considerable interest as electrochemical sensors because they provide better sensing responses to different analytes. We report the synthesis of rod like polypyrrole (PPY)-Ag nanocomposite using sodium cholate as soft-template for sensing nanomolar concentration of dopamine (DA). The nanocomposites were characterized by employing FT-IR, XRD, scanning and transmission electron microscopic analysis. Electrochemical impedance spectroscopy and cyclic voltammetry experiments were performed for electrochemical characterization of the PPY-Ag nanocomposite deposited on glassy carbon electrode (GCE). Electrochemical detection of DA using this nanocomposite deposited on GCE was done following linear sweep voltammetry. The PPY-Ag nanocomposite deposited electrode showed improved sensitivity value of 8.22 mAμM−1 for DA and a detection limit of 0.00005 μM. Biocompatibility assay of the developed PPY-Ag nanocomposites have exhibited less toxicity to mouse fibroblast cell even in comparison to that of PPY without silver. Antimicrobial property of the PPY-Ag nanocomposites towards E.coli and S. Aureus have also been observed.