Electrochemical detection platform based on graphene-zinc oxide composite nanomaterials for 17β-estradiol determination in milk

This research presents the development of an innovative electrochemical detection platform using a graphene-zinc oxide (G-ZnO) nanocomposite for the quantification of 17β-estradiol in milk. The G-ZnO nanocomposite, synthesized via a facile one-pot method, exhibited a unique wrinkled structure with a high specific surface area of 143 m²/g. Characterization through SEM, TEM, and XRD confirmed the effective integration of ultrafine ZnO nanoparticles onto graphene sheets. The electrochemical performance of the G-ZnO modified glassy carbon electrode was evaluated, revealing a notably low detection limit of 8.3 nM for 17β-estradiol, a significant improvement over traditional sensors. The sensor demonstrated a wide linear range of 0.05–100 μM and exceptional reproducibility with less than 3.5 % RSD over repeated measurements. Recovery studies in spiked milk samples yielded highly accurate results, with recovery percentages ranging from 97.8 % to 104.6 %. These findings underscore the potential of G-ZnO nanocomposites in creating sensitive, efficient, and reliable sensors for healthcare and environmental applications.