Selective Array-Based Sensing of Anabolic Steroids in Aqueous Solution by Host-Guest Reporter Complexes.

Arrayed complexes of a water-soluble deep cavitand and two fluorescent indicators show selective sensing of anabolic-androgenic steroids in aqueous environments. By combining the host-guest complexes with small amounts of heavy metal ions, discrimination between steroids that vary in structure by only a single π bond is possible. The sensing occurs through a triggered aggregation mechanism, which can be mediated by both the presence of metal ions and the steroids. The use of both "turn-on" and "turn-off" fluorophores is essential for good discrimination. As low as 10 µm steroid can be detected, and the discrimination is selective in steroid samples spiked into human urine.