Colorimetric determination of 17β-estradiol based on the specific recognition of aptamer and the salt-induced aggregation of gold nanoparticles

An aptamer-based colorimetric method for the detection of 17 beta-estradiol was established by employing AuNPs as the colorimetric probe. This assay was based on the principle that the salt-induced aggregation of AuNPs could be controlled by the adsorption of aptamers on the surface of AuNPs, which was modulated by the specific recognition of aptamers with targets. The method was successfully applied for tap water samples with satisfactory recoveries, which were in full consistence with the results from HPLC. The response of 17 beta-estradiol was much higher than that of other endocrine-disrupting compounds and several probably coexisting chemicals. The advantages of simplicity, rapidity and selectivity, make this method a useful tool for the determination of 17 beta-estradiol in real samples. (C) 2015 Elsevier B.V. All rights reserved.