Indicator displacement assays are based on the optical signal modulation of a noncovalently bound indicator upon dissociation by an analyte species. Our work has focused on exploring the lower detection limits for luminescent displacement assays for inorganic phosphate in seawater using complex ions containing two di(2-picolyl)amine ligands (also called DPA or bis(2-pyridylmethyl)amine), each coordinating a zinc cation. Following the work of B.D. Smith and coworkers we have prepared three ligands by covalently attaching two DPA moieties 2,6-bis(chloromethyl) benzene, and 2,6-bis(chloromethyl)-4-methylphenol, and 1,2-phenylenedimethylamine for assays with 6,7-dihydroxy-4-methanesulfonic acid coumarin. We are also exploring luminescent assays with ruthenium and iridium complex ions with a bipyridyl ligand functionalized with two DPA ligands. To-date, our limit of detection for a simple fluorescence assay is on the order of 10 ppb in the presence of 0.1 M NaCl.

Exploring indicator displacement assays for phosphate detection in seawater

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.