DNA Origami-Based Luminescent Biosensors Enabling Smartphone Detection of Nucleic Acid Sequences

DNA origami enables the precise assembly of complex nanostructures, facilitating the visual detection of various molecular targets. Previously, we developed DNA origami-based nanosensors, termed "pliers", which allowed the detection of inorganic and organic single-molecule targets through shape transitions. However, these methods require costly analytical instruments, such as atomic force microscopy and fluorescence detection. To establish a more accessible and quantitative detection approach, we developed a luminescence-based DNA origami biosensor for nucleic acid detection. By redesigning the sensor module, we improved the structural stability and sensitivity. The integration of split luciferase enabled signal amplification proportional to the target RNA concentration, allowing for precise detection using a smartphone. Additionally, combining this method with PCR successfully detected as few as 100 copies of Escherichia coli plasmid DNA. This DNA origami-based biosensor provides a promising platform for cost-effective and portable nucleic acid detection, with potential applications in pathogen diagnostics.