▎ 摘　　要

A sensitive voltammetric biosensor based on silver nanoparticles (AgNPs) and electrochemically reduced graphene oxide (ErGO) nanocomposite modified pyrolytic graphite (AgNPs: ErGO/PG) has been prepared to determine the effect of caffeine (CAF) on the concentration of estradiol (EST) in the child-bearing aged women (18-35 yr). The modified surface was characterized by Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), Electrochemical Impedance Spectroscopy (EIS), Raman Spectroscopy, cyclic voltammetry (CV) and square wave voltammetry (SWV). The modified sensor exhibited exceptional electrocatalytic effects towards the oxidation of EST and CAF with a significant enhanced peak current. The linear calibration curves were found in the concentration range of 0.001-175 mu M and 0.001-200 mu M for EST and CAF respectively and the limits of detection were found as 0.046 nM, and 0.54 nM. The common metabolites present in the biological fluid matrix i.e. ascorbic acid (AA), uric acid (UA), xanthine (XT) and hypoxanthine (HX) did not interfere in the simultaneous determination of EST and CAF. The analytical applicability of the proposed sensor has been exhibited by analyzing EST and CAF in the human serum and urine samples of five women of child-bearing age.