Defect Engineering of DNA Origami ROS Sensors for Portable Urinalysis

ABSTRACT

Translating in situ dynamic changes of key signaling molecules into actionable clinical readouts remains a formidable challenge for noninvasive diagnostics. Here, focusing on reactive oxygen species (ROS) as pivotal signaling mediators, we developed defect‐programmed DNA origami ROS sensors (DOSs) for portable urinalysis of localized oxidative stress. Using triangular DNA origami (DO) nanostructures as two‐dimensional synthetic soft crystals, we programmed the number of discontinuity defects between adjacent staple strands and established a positive correlation between defect number and ROS‐triggered degradation kinetics. To transform this programmable degradation into a diagnostic function, we then engineered DOSs via orthogonal assembly of targeting and signaling modules onto DO. In a murine model of acute liver injury (ALI), DOSs selectively accumulated in the liver and underwent ROS‐triggered fragmentation into renal‐clearable debris, converting hepatic ROS levels into quantifiable urinary signals. Notably, this transformation efficiency depended positively on defect number in DOSs, enabling portable urinalysis that detected ALI onset at least 4 h earlier than conventional alanine aminotransferase (ALT) testing, with a maximum area under the curve of 0.94. This defect‐engineering strategy establishes a generalizable platform for early, noninvasive diagnosis of ROS‐related diseases.