Francis Radics ’22
Exploring Indicator Displacement Assays for Phosphate Detection in Seawater
Francis Radics ’22, Biochemistry
Faculty Mentor: Dr. John Breen, Chemistry and Biochemistry
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.
Poster Presentation: Thursday, April 28, 2 – 4 p.m.
