Tuberculosis (TB) is one of the top ten causes of death globally, despite being treatable. The eradication of TB disease requires, amongst others, diagnostic tests with high specificity and sensitivity that will work at the point of care (POC) in low-resource settings. The TB surface glycolipid antigen, mannose-capped lipoarabinomannan (ManLAM) currently serves as the only POC molecular diagnostic biomarker suitable for use in low cost immunoassays.
View Article and Find Full Text PDFMulti-antigen rapid diagnostic tests (RDTs) are highly informative, simple, mobile, and inexpensive, making them valuable point-of-care (POC) diagnostic tools. However, these RDTs suffer from several technical limitations-the most significant being the failure to detect low levels of infection. To overcome this, we have developed a magnetic bead-based multiplex biomarker enrichment strategy that combines metal affinity and immunospecific capture to purify and enrich multiple target biomarkers.
View Article and Find Full Text PDFRapid diagnostic tests (RDTs) designed to function at the point of care are becoming more prevalent in malaria diagnostics because of their low cost and simplicity. While many of these tests function effectively with high parasite density samples, their poor sensitivity can often lead to misdiagnosis when parasitemia falls below 100 parasites/l. In this study, a flow-through pipette-based column was explored as a cost-effective means to capture and elute more histidine-rich protein II (HRPII) antigen, concentrating the biomarker available in large-volume lysed whole blood samples into volumes compatible with -specific RDTs.
View Article and Find Full Text PDFIn many diagnostic assays, specific biomarker extraction and purification from a patient sample is performed in microcentrifuge tubes using surface-functionalized magnetic beads. Although assay binding times are known to be highly dependent on sample viscosity, sample volume, capture reagent, and fluid mixing, the theoretical mass transport framework that has been developed and validated in engineering has yet to be applied in this context. In this work, we adapt this existing framework for simultaneous mass transfer and surface reaction and apply it to the binding of biomarkers in clinical samples to surface-functionalized magnetic beads.
View Article and Find Full Text PDFDiagnosis of asymptomatic malaria poses a great challenge to global disease elimination efforts. Healthcare infrastructure in rural settings cannot support existing state-of-the-art tools necessary to diagnose asymptomatic malaria infections. Instead, lateral flow immunoassays (LFAs) are widely used as a diagnostic tool in malaria endemic areas.
View Article and Find Full Text PDFThis work outlines the synthesis of a non-emissive, cyclometalated Ir(III) complex, Ir(ppy)2(H2O)2(+) (Ir1), which elicits a rapid, long-lived phosphorescent signal when coordinated to a histidine-containing protein immobilized on the surface of a magnetic particle. Synthesis of Ir1, in high yields,is complete O/N and involves splitting of the parent cyclometalated Ir(III) chloro-bridged dimer into two equivalents of the solvated complex. To confirm specificity, several amino acids were probed for coordination activity when added to the synthesized probe, and only histidine elicited a signal response.
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