Label free biosensor for screening estrogenic activity

Hormone mimics known as endocrine disrupting compounds (EDCs) prevalent in aquatic environment are of great environmental concern because of their endocrine disrupting and carcinogenic effects. Looking to the wide variety of natural as well as synthetic estrogen hormone mimics, a reliable in-vitro assay is required to screen the estrogenic activity. Surface plasmon resonance (SPR) is one of the most promising analytical tools to monitor high-performance biomolecular interaction in real time without labelling. Present paper demonstrates a facile SPR based affinity bioassay employing estrogen receptor-α, human (hERα) functionalized self assembled monolayer covalently bound to the gold sensor chip as recognition species. A successful interaction of suspect hormone mimic with estrogen receptor is evidenced by net rise in SPR angle in real time. The assay has been validated in terms of optimum experimental conditions and specificity with estrogen as standard showing maximum estrogenic activity. As a proof of concept, proposed affinity assay is tested for screening the estrogenic activity of progesterone, pregnenolone, tamoxifen, and bisphenol-A as representative examples of potential EDCs of different classes.