Nano-foam gold-modified diamond electrochemical aptasensing platform for ultrasensitive monitoring of 17β-estradiol†

This study developed a nano-foam gold modified boron-doped diamond (NFG/BDD-Apt) electrochemical aptasensor through a synergistic electrodeposition-dealloying strategy combined with aptamer functionalization for detecting 17β-estradiol (E2) in aquatic environments. The NFG/BDD-Apt sensor was systematically characterized using SEM, Raman, and EIS to elucidate its surface morphology, molecular structure, and electrochemical properties. SEM analysis revealed the successful formation of a homogeneous three-dimensional porous NFG structure on the BDD surface, which significantly enhanced the specific surface area (1.9-fold increase vs. bare BDD) and electron transfer efficiency. Electrochemical performance evaluation through CV and DPV demonstrated superior E2 detection capabilities. Under optimized conditions, the sensor exhibited a wide linear response range from 1.0 × 10⁻¹⁴ to 1.0 × 10⁻⁸ mol L⁻¹ (R² = 0.997) with an ultralow detection limit of 1.8 × 10⁻¹⁵ mol L⁻¹ (S/N = 3). NFG/BDD-Apt demonstrated exceptional selectivity (>92% specificity against common interferents) and long-term stability. This work provides a novel sensing platform combining diamond electrode advantages with nanostructured amplification effects, offering significant potential for rapid and reliable monitoring of endocrine disruptors in environmental water systems.