ScholarWorks@중앙대학교

초록

Harmful algal blooms (HAB), intensified by climate change and eutrophication, pose severe risks to freshwater ecosystems and public health, particularly in communities relying on surface water as drinking sources. Effective HAB surveillance requires rapid and reliable molecular detection tools that can be deployed directly in the field, yet most existing methods for detecting dominant freshwater cyanobacteria remain laboratory-bound, lacking the portability and affordability needed for on-site use. Here, we introduce the point-of-care testing polymerase chain reaction (POCT-PCR) device, a handheld, battery-powered thermocycler (1.0 kg, US$97) designed for on-site DNA amplification. The system integrates an aluminum heat sink, dual ceramic heaters, a Peltier-based cooling module, and a fast-response thermistor all governed by Arduino-based PID control. Using custom mini-PCR tubes with a 30 μL capacity, substantially smaller than the conventional 100 μL PCR tubes, to enhance thermal transfer and significantly minimize evaporation, the POCT-PCR achieves ramp rates of +1.10°C/s and –1.95°C/s, enabling fast and stable thermal cycling (30 cycles in 78 min). Validation assays confirmed reliable amplification of eleven cyanobacterial genes, including those associated with toxin-producing strains, with reproducibility comparable to benchtop systems. Field validation further confirmed the device’s robustness and applicability under real environmental conditions. This low-cost platform enables rapid ecological surveillance and supports early-warning applications for harmful cyanobacterial blooms, expanding access to point-of-care molecular diagnostics for environmental and public health protection.

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