SUMMARY

The ability to rapidly, sensitively, and accurately detect the presence of a pathogen is a vital capability for first responders in the assessment and treatment of scenarios such as disease outbreak and bioterrorism. Nucleic acid tests such as the polymerase chain reaction (PCR) are supplanting traditional techniques due to the improved speed, specificity, sensitivity, and simplicity. Still, amplification by PCR is often the bottleneck when processing genetic samples. Conventional PCR machines are bulky, slow, and consume large reagent volumes and an affordable, compact, efficient, easy-to-use alternative has yet to emerge. In this work, a microfluidic PCR platform was developed consisting of a low-cost, multi-chamber polymer microchip and a laser-mediated thermocycler capable of independent thermal control of each reaction chamber. Innovations in polymer microchip modeling, fabrication, and characterization yielded a low-cost solution for sample handling. A simple optical system featuring an infrared laser diode and solenoid-driven optical shutter was combined with a microfluidic temperature measurement system utilizing embedded thermocouples to achieve rapid thermocycling capable of multiplexed temperature control. We validated the instrument with sensitive amplifications of multiple viral targets simultaneously. This technology is a breakthrough in practical microfluidic PCR instrumentation, providing the foundation for a paradigm shift in low-cost, high-throughput genetic diagnostics.