Nitrite determination at electrochemically synthesized polydiphenylamine-Pt composite modified glassy carbon electrode

Platinum nanoparticles found very wide application in electrocatalysis and sensor. However, Pt must be deposited in a stable matrix to increase stability and avoid fouling. In this work polydiphenylamine-Pt (PDPA-Pt) composite has been synthesized by electrochemical method on glassy carbon electrode. PDPA-Pt has been characterized by scanning electrochemical microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The SEM studies showed well dispersed Pt nanoparticles on PDPA surface. The electrocatalytic activity of PDPA-Pt film modified electrode toward the oxidation of NO2−was studied by cyclic voltammetry and amperometry. Cyclic voltammograms showed that NO2−undergoes irreversible oxidation at 0.85 V at PDPA-Pt modified electrode which is 0.33 V less than that of bare GCE. This shows the efficient electrocatalytic activity of the composite film. The electroanalytical application of the composite film was done by amperometric technique. The film shows a response time of less than 1 s and wide linear range of detection from 1 μM to 9.5 mM. PDPA-Pt is a promising material for electrochemical and biosensor applications. The good recoveries achieved in the various water samples for the determination of nitrite shows the practicality of the proposed sensor.