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dc.contributor.authorAkki, Spurti U.
dc.contributor.authorWerth, Charles J.
dc.contributor.authorSilverman, Scott K.
dc.date.accessioned2016-02-28T05:53:36Z
dc.date.available2016-02-28T05:53:36Z
dc.date.issued2015-07-31
dc.identifier.citationAkki SU, Werth CJ, Silverman SK (2015) Selective Aptamers for Detection of Estradiol and Ethynylestradiol in Natural Waters. Environ Sci Technol 49: 9905–9913. Available: http://dx.doi.org/10.1021/acs.est.5b02401.
dc.identifier.issn0013-936X
dc.identifier.issn1520-5851
dc.identifier.pmid26182235
dc.identifier.doi10.1021/acs.est.5b02401
dc.identifier.urihttp://hdl.handle.net/10754/599573
dc.description.abstract© 2015 American Chemical Society. We used in vitro selection to identify new DNA aptamers for two endocrine-disrupting compounds often found in treated and natural waters, 17β-estradiol (E2) and 17α-ethynylestradiol (EE). We used equilibrium filtration to determine aptamer sensitivity/selectivity and dimethyl sulfate (DMS) probing to explore aptamer binding sites. The new E2 aptamers are at least 74-fold more sensitive for E2 than is a previously reported DNA aptamer, with dissociation constants (Kd values) of 0.6 μM. Similarly, the EE aptamers are highly sensitive for EE, with Kd of 0.5-1.0 μM. Selectivity values indicate that the E2 aptamers bind E2 and a structural analogue, estrone (E1), equally well and are up to 74-fold selective over EE. One EE aptamer is 53-fold more selective for EE over E2 or E1, but the other binds EE, E2, and E1 with similar affinity. The new aptamers do not lose sensitivity or selectivity in natural water from a local lake, despite the presence of natural organic matter (∼4 mg/L TOC). DMS probing suggests that E2 binding occurs in relatively flexible single-stranded DNA regions, an important finding for rational redesign of aptamers and their incorporation into sensing platforms. This is the first report of aptamers with strong selectivity for E2 and E1 over EE, or with strong selectivity for EE over E2 and E1. Such selectivity is important for achieving the goal of creating practically useful DNA-based sensors that can distinguish structurally similar estrogenic compounds in natural waters.
dc.description.sponsorshipThis work was partially supported by grants to C.J.W. from WaterCAMPWS, a Science and Technology Center program of the National Science Foundation under Agreement No. CTS(0120978, and from King Abdullah University of Science and Technology.
dc.publisherAmerican Chemical Society (ACS)
dc.titleSelective Aptamers for Detection of Estradiol and Ethynylestradiol in Natural Waters
dc.typeArticle
dc.identifier.journalEnvironmental Science & Technology
dc.contributor.institutionUniversity of Illinois at Urbana-Champaign, Urbana, United States
dc.contributor.institutionUniversity of Texas at Austin, Austin, United States
dc.date.published-online2015-07-31
dc.date.published-print2015-08-18


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