Electrochemical sensor based on porous gold screen-printed electrode in flow analysis system for sensitive determination of hydrogen peroxide

Abstract

A non-enzymatic electrochemical sensor for the determination of hydrogen peroxide (H2O2) in milk samples was developed using porous gold (pAu) modified on a gold screen-printed electrode (AuSPE). A simple one-step method for electrodeposition of pAu modified on a AuSPE using a small 9 V battery as a voltage source. The pAu- AuSPE was evaluated with a flow injection amperometric (Fl-amperometric) system. The proposed FI system was able to detect H2O2 in the linear range of 10 to 1000 uM with a limit of detection (LOD) of 0.38 uM. The relative standard deviation (RSD) for 100 replicated injections of 100 uM H:02 was 1.95%. The pAu-AuSPE can be used continuously with a sample throughput of 60 injections per hour. In addition, the Fl- amperometric system incorporates with a dialysis unit was developed for the determination of H2O2 in the milk sample to provide a convenient sample preparation and interference eliminating from the sample matrices. The proposed method was successfully applied for the determination of H2O2 in the milk sample, with recoveries in the range of 90 - 109%. The developed system provided advantages of rapid, high stability, good repeatability, and without suffering from colloidal substances presented in the milk sample.