Electrochemical immunosensor for rapid and sensitive determination of estradiol

► An electrochemical immunosensor for estradiol based on grafted SPCEs was developed. ► Grafting of p-aminobenzoic acid on SPCEs and streptavidin covalent binding was used. ► A low LOD, 0.77 pg mL−1, and a wide linear range, 1.0-250 pg mL−1, were obtained. ► Validation was made by analyzing human serum and urine.