DaimonDNA: a portable, low-cost loop-mediated isothermal amplification platform for naked-eye detection of genetically modified organisms in resource-limited settings

The steady increase in commercialization of genetically modified organisms (GMOs) demands low-cost, rapid and portable GMO-detection methods that are technically and economically sustainable. Traditional nucleic acid amplification and detection platforms are still expensive, immobile and generate complex read-outs to be analyzed by experienced personal. Herein, we report the development of a portable, rapid and user-friendly GMO-detection biosensor, DaimonDNA. The system specifically amplifies the target DNA using loop-mediated isothermal amplification (LAMP) and provides real-time, naked-eye detection with Hydroxynaphthol blue reagent in less than 30 minutes. The construction of the platform relies on 3D printing and off-the-shelf electronic components that makes it extremely low-cost (< 25 Euro), light weight (108 g), mobile (6 x 6 x 3 cm) and suitable for field deployment. We demonstrated the stability of the time-dependent temperature curves of the samples during the LAMP reaction. We present the detection of the soybean lectin gene as a species control, and P35S as a transgene element found in many GMO varieties. We confirmed specificity of the DaimonDNA biosensor using ”RoundUp Ready (RRS)” and MON89788 soybean genomic DNA with P35S and lectin primer sets. We characterized sensitivity of our system using 0.1%, 1% and 10% dilutions of the RRS soybean genomic DNA. We benchmarked the DNA amplification and detection efficiency of our system against a thermocycling machine by quantifying the images obtained from gel electrophoresis, and showed that our system is comparable to most other reported isothermal amplification techniques. This system can also be used for widespread point-of-care or field-based testing that is infrequently performed due to the lack of rapid, inexpensive, user-friendly and portable methods