Tungsten‐Boosted Erbium Oxide–Graphene Nanoplatelet Electrode for Voltammetric Determination of Metaproterenol

ABSTRACT In this study, an electrochemical sensor was developed by modifying a glassy carbon electrode (GCE) with a nanostructured composite of graphene nanoplatelets (GNPs), ultrasound‐assisted synthesized erbium oxide (Er 2 O 3 ), and tungsten (W) nanoparticles. The platform (W@Er 2 O 3 ‐GNPs/GCE) exhibited favorable electrochemical characteristics, including a relatively low charge transfer resistance (Rct = 136 Ω) and an enlarged electroactive surface area (A = 0.227 cm 2 ). The modified electrode exhibited enhanced electrocatalytic activity toward the oxidation of metaproterenol, as evidenced by the increased oxidation peak current and the shift of the oxidation peak potential (Epa) toward less positive potentials. This enhanced performance is attributed to the complementary contributions of GNPs, which provide a high‐surface‐area conductive framework, and Er 2 O 3 @W nanoparticles, which provide additional electroactive sites and favorable interfacial properties for the oxidation of metaproterenol. The developed platform exhibited a linear working range of 2.4 × 10 −7 –1.4 × 10 −5 M, an analytical sensitivity of 0.5732 µA µM −1 , and a low detection limit of 3.0 × 10 −8 M. The proposed method also demonstrated repeatability with an RSD < 1.5% over 10 scans, storage stability with a signal loss <4.0% after 15 days of storage, and satisfactory recoveries in complex media.