An electrochemical facile fabrication of platinum nanoparticle decorated reduced graphene oxide; Application for enhanced electrochemical sensing of H₂O₂

In the present work, we report a single step electrochemical fabrication of a platinum nanoparticle decorated reduced graphene oxide (RGO-PtNPs) composite for enhanced electrochemical sensing of hydrogen peroxide (H₂O₂). The RGO-PtNPs composite was fabricated by the reduction of graphene oxide modified electrode in an electrolyte solution containing a 0.5 mM K₂PtCl₆ solution with 1 mM KCl at a constant applied potential of -1.4 V for 300 s. The fabricated composite modified electrode was further characterized by scanning electron microscopy, elemental analysis and cyclic voltammetry. Compared with GO-PtNPs and PtNPs modified electrodes, the RGO-PtNPs composite modified electrode showed an enhanced electrocatalytic activity toward the reduction of H₂O₂. The amperometric response of the RGO-PtNPs composite modified electrode for the reduction of H₂O₂ was linear over the concentration ranging from 0.05 to 750.6 μM with the limit of detection of 16 nM. The sensor reached its steady state current response within 2 s. The sensitivity of the sensor was calculated as 0.686 + 0.072 μA μM^-1 cm^-2. The proposed sensor showed a satisfactory selectivity in the presence of biologically coactive compounds. In addition, the sensor also showed a good practicability toward the detection of H₂O₂ in commercial contact lens solutions and human urine samples.