Selectivity study towards 17α-ethinylestradiol (EE2) detection based on silica microsphere-gold nanoparticle

The widespread use of 17α-Ethinylestradiol (EE2), a synthetic estrogen female hormone with potent physiological effects at lower concentrations than other steroids, poses environmental and health concerns due to its weak electrochemical behavior. Current detection methods lack the requisite sensitivity and selectivity for precise EE2 monitoring, posing potential risks in diverse environments. A critical need exists for a high-performance electrochemical biosensor to address these limitations and selectively detect EE2 with enhanced sensitivity. This development is crucial for accurate monitoring and risk assessment in the context of EE2 exposure. Silica nanoparticles offer advantageous features such as high surface area, excellent stability, large pore volume, adjustable shape, and size, simplicity of production, and biocompatibility. Additionally, gold nanoparticles are effective in facilitating electron transfer processes. Characterization through cyclic voltammogram (CV) and differential pulse voltammogram (DPV) revealed that the anodic peak current of electrodes modified with both silica and gold surpasses that of electrodes modified with silica or gold alone. Notably, the anodic peak current exhibits an upward trend with increasing concentrations of EE2, emphasizing the heightened sensitivity achieved through the incorporation of silica and gold in the electrode modification. The current of the anodic peak was linear within the range 110-6 -110-4 M EE2 concentration with linear regression equation Ipa (A) = 1.639CEE2 + 120.55 and R2=0.939. It may be seen that the electrochemical biosensor is superior in performance, due to the presence of the silica and gold that provides sensitivity for EE2 detection. Furthermore, in terms of selectivity, it was found that this sensor possessed acceptable performance in terms of selectivity through E3 which gained an overall percentage change of 0.04%, while E2 gained an overall percentage change of 10.23%, which is considered a good selectivity specifically for E3. The incorporation of silica and gold nanoparticles in electrode modification resulted in a noteworthy outcome: the anodic peak current surpassed that of electrodes modified with silica or gold alone. This increase in current intensity exhibited a direct correlation with the rise in concentrations of EE2, highlighting the enhanced sensitivity achieved through the synergistic combination of silica and gold nanoparticles.