Flow injection non-enzymatic amperometric detection of hydrogen peroxide based on a glassy carbon electrode modified with silver particles on glassy carbon spherical powder

This work reports the development of a non-enzymatic electrochemical sensor for hydrogen peroxide based on a glassy carbon electrode modified with glassy carbon spherical powder carrying silver particles (AgPs-GCS/GCE). In this work, AgPs were synthesized on GCS by electroless deposition. The surface morphology and electrochemical behavior of the AgPs-GCS/GCE were characterized by scanning electron microscopy (SEM) and cyclic voltammetry, respectively. The average diameter of the AgPs on GCS was 673 ± 89 nm. The AgPs-GCS/GCE exhibited excellent electrocatalytic activity for the reduction of hydrogen peroxide. The proposed modified electrode was incorporated in a flow injection amperometry system (FI-Amp). The optimized fabrication and operational conditions included the amount of AgPs-GCS covering the GCE, and the applied potential, flow rate and sample volume. Under optimal conditions, the proposed method provided a wide linear range (0.25–350 μg mL−1) (r = 0.999) with high sensitivity (5.75 μA mg L−1 cm−2). The limit of detection (LOD) and limit of quantitation (LOQ) were 0.12 μg mL−1 and of 0.38 μg mL−1, respectively. This sensor exhibited good repeatability (RSD 1) and the developed method successfully detected hydrogen peroxide in hair dyes and cotton samples with good recoveries (90 ± 2% to 106 ± 2%). © 2018 The Electrochemical Society.