Real-time in situ determination of free Cu(II) at picomolar levels in sea water using a fluorescence lifetime-based fiber optic biosensor

A continuing issue in chemical oceanography and environmental monitoring is the need for frequent and continuous monitoring of analytes in complex matrices such as sea water and ground waters. Particularly for analytes at trace levels such as Cu(II) in sea water, sampling and analysis of discrete specimens is costly, slow, labor intensive, employs ship time inefficiently, and risks error by contamination. We have developed a fluorescence lifetime-based fiber optic biosensor which demonstrates real time determination of free Cu(II) in coastal waters, in situ, with a subpicomolar detection limit.