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 mu g mL(-1)) (r = 0.999) with high sensitivity (5.75 mu A mg L-1 cm(-2)). The limit of detection (LOD) and limit of quantitation (LOQ) were 0.12 mu g mL(-1) and of 0.38 mu g mL(-1), respectively. This sensor exhibited good repeatability (RSD < 5.7%), good stability (RSD = 1.98%, n = 170), and high sample throughput (90 samples h(-1)) and the developed method successfully detected hydrogen peroxide in hair dyes and cotton samples with good recoveries (90 +/- 2% to 106 +/- 2%). (C) 2018 The Electrochemical Society.