A New Molecular Imprinting-Based Mass-Sensitive Sensor for Real-Time Detection of 17β-Estradiol from Aqueous Solution

The 17-estradiol (E2), natural steroid hormone, is one of the most potent endocrine disrupting compounds even at ng L-1 levels. Its rapid, selective and sensitive detection is intensively required. In this study, quartz crystal microbalance (QCM) sensor was prepared for real-time monitoring of E2 in water samples, through the attachment of E2 imprinted nanoparticles, synthesized by mini-emulsion polymerization, on the gold surface of QCM sensor. QCM sensor surface was characterized by atomic force microscopy (AFM), ellipsometer, and contact angle measurements. The specificity of the QCM nanosensor was shown by competitive adsorption of E2, stigmasterol and cholesterol. The results showed that QCM nanosensor has high selectivity and sensitivity for E2 even in a wide range of 3.67 nM-3.67 pM. The detection and quantification limits were calculated as 613 fM and 2.04 pM, respectively. According to the results, the proposed molecular imprinted QCM nanosensor is promising cost-friendly alternative for quantification of E2 from ground water. (c) 2012 American Institute of Chemical Engineers Environ Prog, 32: 1164-1169, 2013