MODIFIED PRUSSIAN BLUE SCREEN PRINTED ELECTRODES FOR H2O2 DETECTION

Abstract

In this work, presents recent developments in the electrochemical application of disposable screen-printed sensors, to the type of materials used to modify the working electrode.The sensor was based on the electrocatalytic reduction of H₂O₂ on Prussian Blue modified screen-printed electrode. A comparative study regarding different procedures for modifying the carbon screen-printed electrodes (SPE) with Prussian Blue (PB) was carried out in this work. Two procedures for PB deposition on the SPE electrodes were tested: electrochemical deposition (galvanostatic, cyclic voltammetry) and chemical deposition by the reaction of K₃[Fe(CN)₆] with FeCl₃.Also, the influence of the pretreatment of SPE (+1.7V for 3 min in PBS, pH 7.4) and of the stabilization of PB deposited on SPE (by heating at 100°C) were evaluated. The developed sensors were optimized with respect to the lowest limit of detection achieved for amperometric detection of H₂O₂. Analytical parameters, such as detection limit, linearity range and sensitivity have been evaluated, together with operational and storage stability. The improved electro-deposition methods, pH stability and permeability of the optimized PB film provide a further boost in its sensitivity for H₂O₂ detection, which is a critical parameter in biosensor design and application.