In JoVE (1)
Other Publications (1)
Articles by Anna L. Bitting in JoVE
Iridium(III) Luminescent Probe for Detection of the Malarial Protein Biomarker Histidine Rich Protein-II Keersten M. Davis1, Anna L. Bitting1, Christine F. Markwalter1, Westley S. Bauer1, David W. Wright1 1Department of Chemistry, Vanderbilt University Robust detection reagents are of increasing necessity for developing new malaria diagnostic tools. An iridium(III) probe was designed that emits long-lasting luminescent signal in the presence of a histidine-rich malarial protein biomarker. Detection of the protein either in solution or immobilized on a magnetic particle affords flexibility in application.
Other articles by Anna L. Bitting on PubMed
On-particle Detection of Plasmodium Falciparum Histidine-rich Protein II by a "switch-on" Iridium(III) Probe Analytical Biochemistry. Jan, 2014 | Pubmed ID: 24129120 The need for robust reagents for biomarker detection has become an increasing necessity in designing point-of-care diagnostics. We report a non-emissive, cyclometalated iridium(III) complex, Ir(ppy)2(H2O)2(+) (Ir1), which, on coordination to a histidine-containing protein bound to the surface of a magnetic particle, elicits a rapid, long-lived phosphorescent signal. The interactions between Ir1 and numerous other amino acids were examined for activity, but only the addition of histidine resulted in a four orders of magnitude enhancement in signal intensity. Buffer conditions (pH and temperature) and composition (coordinating vs. non-coordinating and ionic strength) were optimized to achieve maximum signal and stability of Ir1. The activity of the probe under optimized conditions was validated with BNT-II, a histidine-containing branched peptide mimic of the malarial biomarker Plasmodium falciparum histidine-rich protein II (PfHRPII). By comparing Ir1 binding to BNT-II versus L-histidine, steric and quenching effects were noted in the peptide. Despite these deviations from ideal conditions, signal response reached saturation with both BNT-II and recombinant HRPII (rcHRPII). When immobilized on the surface of a 50 μM magnetic agarose particles, the limit of detection of rcHRPII was 14.5 nM. The robust signal response of this inorganic probe lends itself to future applications in on-particle enzyme-linked immunosorbent assay (ELISA)-based assays.