Reactive indicator for use in an enzyme-linked immunosorbent assay

CHED 432

Allison J. Johnson, AJJOHNSON5@stthomas.edu and J. Thomas Ippoliti, jtippoliti@stthomas.edu. Department of Chemistry, University of Saint Thomas, 2115 Summit Ave, OSS 402, Saint Paul, MN 55105
It was recently discovered that conversion of aryl boronates to phenols provides a reaction-based approach to specific fluorescence detection of H2O2. An enzyme-linked immunosorbent assay (ELISA) based on this conversion has been exploited in this research. A boronate ester of resorufin, a fluorescent indicator was synthesized. The synthesis starts with the treatment of the sodium salt of resorufin with N-phenyl bis(trifluoromethanesulfonamide) to afford a triflate. The triflate is converted to a boronate ester via a palladium-catalyzed borylation. This molecule serves as a latent fluorophore for an ELISA that produces H2O2. The fluorescent intensity was measured to be 7.2 times greater than a fluorescein based boronate ester and reacts with H2O2 about 4 times as fast as that ester.