Solid-state synthesis of Ag-doped PANI nanocomposites for their end-use as an electrochemical sensor for hydrogen peroxide and dopamine

•Solid-state synthesis of Ag-doped PANI nanocomposites.•Ag-doped PANI nanocomposites based GCE successfully applied for the electrochemical sensing of H2O2 and DA.•CV, DPV, and amperometry techniques confirmed the reduction of H2O2 and the oxidation of DA to DA quinone.•For H2O2 and DA, the detection limits as measured from current-time chronoamperometry were 0.03 µM and 0.12 µM, respectively, from DPV. Polyaniline protected silver nanoparticles (Ag-doped PANI nanocomposites) were synthesized successfully by a solid-state mechano-chemical oxidative polymerization. AgNO3 acted as a metal precursor as well as an oxidizing agent. The prepared Ag-doped PANI nanocomposites were characterized by various techniques such as TEM, FE-SEM, XRD, FTIR and UV–vis spectroscopy. XRD confirmed the cubic FCC form of the Ag nanoparticles with an average crystal size of ~36.04 nm for the Ag-doped PANI nanocomposites. FE-SEM and TEM analysis of Ag-doped PANI nanocomposites revealed the formation of spherical as well as semi-spherical Ag nanoparticles embedded in the PANI polymer matrix. Cyclic voltammogram revealed excellent electrochemical responses and electrocatalytic behavior of the Ag-doped PANI nanocomposites/GCE for hydrogen peroxide (H2O2) and dopamine (DA). Based on cyclic, amperometric and differential pulse voltammetric analysis, it was found that H2O2 undergoes reduction whereas DA is oxidized at the surface of the modified Ag-doped PANI nanocomposites/GCE. For H2O2 and DA, the detection limits as measured from differential pulse voltammetric analysis were 0.03 µM and 0.12 µM, respectively. [Display omitted]