Three-Dimensional (3D) Porous Reduced Graphene Oxide Aerogel (RGA) Nanoelectrodes Consisted of Palladium Nanoparticles Embedded in Polyethlyenimine (PEI) for Detection of Bisphenol A and H₂O₂

This research focuses on the development of three-dimensional (3D), hierarchically porous nanoelectrodes, which incorporate palladium nanoparticles within a polyethyleneimine-reduced graphene oxide aerogel (RGA-PEI-Pd). These nanoelectrodes are designed for sensitive detection of bisphenol A (BPA) and hydrogen peroxide (H2O2). The abundant positive charges in polyethyleneimine (PEI) facilitate the formation of a 3D porous structure by connecting to the reduced graphene oxide through carbon-nitrogen bonds, while also anchoring palladium nanoparticles uniformly across the aerogel. This structure maintains the aerogel's porosity.Palladium in its zero-valent (Pd0) and divalent (Pd2+) states plays a crucial role in the catalyst's performance, undergoing redox reactions to alternate between Pd2+ and Pd4+ states. This dynamic contributes to the electrode's ability to effectively oxidize BPA and reduce H2O2. The modified electrode showed low detection limits for BPA (25.5 nM) and H2O2 (16.2 nM) under optimal conditions. Extensive analytical methods, including electrochemical spectroscopy, were employed to delve into the unique electrocatalytic properties of these electrodes.The practical applicability of these electrodes was further demonstrated by their successful use in real-world environmental and biological samples, such as BPA-contaminated water from rivers and lakes, and clinical samples containing MCF-7 cells. The electrodes also exhibited impressive reusability, with recovery rates ranging from 96% to 104.3%.