03/02/2026
By Kwok Fan Chow

The Kennedy College of Science, Department of Chemistry, invites you to attend a Ph.D. Dissertation defense by Evan Reboli entitled “Ultrasensitive Quantitative Detection of HIV and Dengue Viral Antigens and Translation Studies toward Point-of-Care Devices.”

Date: Friday, March 20, 2026
Time: 3 p.m.
Location: Olney Room 518

Committee:

  • Advisor: Suri Iyer, Ph.D., Department of Chemistry, University of Massachusetts Lowell
  • Mingdi Yan, Ph.D., Department of Chemistry, University of Massachusetts Lowell
  • Olof Ramström, Ph.D., Department of Chemistry, University of Massachusetts Lowell
  • James Reuther, Ph.D., Department of Chemistry, University of Massachusetts Lowell

Abstract:
Sensitive and accessible viral diagnostics are essential for early detection, effective treatment monitoring, and reduction of disease transmission, particularly in resource-limited settings where centralized laboratory infrastructure is limited. This dissertation focuses on the development of bioorthogonal multilayer immunoassays for the ultrasensitive detection of HIV and dengue viral antigens, with an emphasis on translating laboratory-grade performance toward accessible diagnostic formats.

Initial chapters establish the clinical importance of HIV-1 p24 as an early biomarker for viral detection and monitoring, as well as the limitations of current point-of-care technologies. Building on this foundation, a multilayer fluorescence enhancement strategy was developed using dye-encapsulated silica nanoparticles coupled through tetrazine–trans-cyclooctene (Tz–TCO) click chemistry. This bioorthogonal approach enables controlled layer-by-layer signal enhancement through rapid, covalent reactions while maintaining assay specificity and quantitative linearity. The resulting system achieved a limit of detection of 20 fg/mL for HIV-1 p24, with a linear dynamic range spanning six orders of magnitude (20 fg/mL to 1 ng/mL), representing approximately a 100-fold improvement over conventional immunoassay methods.

Following validation in the HIV system, the same multilayer fluorescent platform was extended to additional viral targets, including dengue NS1, a secreted non-structural protein biomarker of acute infection. These studies demonstrate the adaptability and modularity of the bioorthogonal enhancement strategy across distinct viral antigens.

Finally, this work explores the translation of the multilayer fluorescence platform into lateral flow assay formats and integrated detection systems. Preliminary studies demonstrate promising quantitative performance, supporting ongoing efforts to bridge ultrasensitive laboratory diagnostics with practical, deployable point-of-care tools capable of expanding access to high-performance viral testing in under-resourced regions.

All interested students and faculty members are invited to attend.