Prussian Blue Modified Submicron Structured Gold Electrodes for Amperometric Hydrogen Peroxide Sensing

Abstract

Abstract In this work, we present a simple and effective approach for fabricating sub‐micron structured gold (SM−Au) electrodes by chemically etching the magnetron co‐sputtered gold film in KI solution for certain time. Such electrodes with a large surface area to volume ratio were used as the matrix for electrochemical deposition of Prussian blue (PB) to develop an electrochemical hydrogen peroxide sensor. Experimental characterization using scanning electron microscope and atomic force microscope shows that the thickness of PB layer on SM−Au electrode is around 140 nm, and is composited with cubic PB nanocrystals. The electrochemical performance of the designed sensor, studied using cyclic voltammograms and chronoamperometry methods, suggests that the sensor based on SM−Au/PB electrode presents the direct electron transfer of PB particle towards SM−Au film, and exhibits fast response, wide linearity, low detection limit and high stability. Under the optimized conditions, the sensitivity of the developed sensor for the detection of H 2 O 2 reaches the value of 512 mA cm −2 M −1 with a linear range from 1 μM to 4.5 mM.