Flow Injection Amperometric Analysis of H 2 O 2 at Platinum Nanoparticles Modified Pencil Graphite Electrode

A Pt nanoparticle modified Pencil Graphite Electrode (PGE) was proposed for the electrocatalytic oxidation and non‐enzymatic determination of H 2 O 2 in Flow Injection Analysis (FIA) system. Platinum nanoparticles (PtNPs) electrochemically deposited on pretreated PGE (p.PGE) surface by recording cyclic voltammograms of 1.0 mM of H 2 PtCl 6 solution in 0.10 M KCl at scan rate of 50 mV s −1 for 30 cycles. Cyclic voltammograms show that the oxidation peak potential of H 2 O 2 shifts from about +700 mV at bare PGE to +50 mV at PtNPs/p.PGE vs. Ag/AgCl /KCl (sat.). It can be concluded that PtNPs/p.PGE exhibits a good electrocatalytic activity towards oxidation of H 2 O 2 . Then, FI amperometric analysis of H 2 O 2 was performed under optimized conditions using a new homemade electrochemical flow cell which was constructed for PGE. Linear range was found as 2.5 μM to 750.0 μM H 2 O 2 with a detection limit of 0.73 μM (based on S b /m of 3). As a result, this study shows the first study on the FI amperometric determination of H 2 O 2 at PtNPs/p.PGE which exhibits a simple, low cost, commercially available, disposable sensor for H 2 O 2 detection. The proposed electrode was successfully applied to determination of H 2 O 2 in real sample.