Title :
Impedance measurements as a tool for the detection of endocrine disrupting chemicals
Author :
Sacks, V. ; Rishpon, J.
Author_Institution :
Dept. of Molecular Microbiol. & Biotechnol., Tel Aviv Univ., Israel
Abstract :
The growing awareness worldwide over the deleterious effects of endocrine disruptors on human health has created a need for screening systems to detect xenoestrogens, a diverse group of chemicals that mimic estrogenic actions and are assumed to decrease male fertility and induce hormone related cancers in females. Here we describe a novel, class-selective detector that uses fast impedance measurements to monitor the binding of estrogen and xenoestrogens to a native estrogen receptor. We embedded the receptor in synthetic lipid bilayers attached to gold electrodes. The lipid bilayers serve as electrical circuits constructed of resistors and capacitors. Estrogen binding to the receptor-modified electrode is immediately followed by conformational changes in the lipid layer, leading to alterations of the electrical circuit components that are detected by fast impedance measurements. The electrochemical system enabled characterization of changes in the bilayer structure and quantification of estrogen binding to the receptor. To assess the effectiveness of the method for detecting estrogenic chemicals, we chose two classes of xenoestrogens: bisphenol-A, a synthetic xenoestrogen, and genistein, a phytoestrogen. This system is highly sensitive and amenable to use on-site, providing an efficient and economic tool for measuring minuscule amounts of endocrine disrupting chemicals in environmental or human samples.
Keywords :
biochemistry; biosensors; chemical sensors; electric impedance measurement; health hazards; lipid bilayers; pollution measurement; proteins; Au; bilayer structure; binding; bisphenol-A; capacitors; class-selective detector; conformational changes; deleterious effects; electrical circuit components; electrical circuits; electrochemical system; endocrine disrupting chemical detection; environmental samples; estrogen binding; estrogenic actions; fast impedance measurements; females; genistein; gold electrodes; hormone related cancers; human health; human samples; impedance measurements; lipid layer; male fertility; native estrogen receptor; on-site; phytoestrogen; receptor-modified electrode; resistors; screening systems; synthetic lipid bilayers; synthetic xenoestrogen; xenoestrogens; Biochemistry; Cancer detection; Chemicals; Circuits; Detectors; Electrodes; Endocrine system; Humans; Impedance measurement; Lipidomics;
Conference_Titel :
Engineering in Medicine and Biology Society, 2001. Proceedings of the 23rd Annual International Conference of the IEEE
Print_ISBN :
0-7803-7211-5
DOI :
10.1109/IEMBS.2001.1017431