Detection of hormone mimics in water using a miniturised SPR sensor

The ubiquitous presence of chemicals, both natural and synthetic, in the environment with the potential to mimic hormones that may in turn interfere with the endocrine system in both wildlife and humans has in the last decade become a major international concern. Hormone mimics or endocrine disrupting compounds (EDCs) are especially prevalent in surface and waste-waters and therefore, there is a need for an at-source or at-line analytical device for the monitoring of EDC levels. We have incorporated a miniature integrated surface plasmon resonance (SPR) liquid sensor from Texas Instruments into a field analyser and developed a competition/inhibition assay for a model estrogenic compound in aqueous samples. The analyser has the potential for in situ and semi-continuous analysis of EDCs. A novel regeneration scheme employing the use of a domestic laundry detergent has been used to remove immobilised assay components between each assay cycle. The resultant re-usable sensor has been demonstrated using estrone-3-glucuronide (E3G) as a model EDC and an anti-E3G antibody producing a current detection range of 10 to 150 ng mL(-1).