From leaf to lab-on-cloth: Spatial DNA nanorobotics and 2D graphyne synergy enable ultra-precise electrochemical tracking of sugarcane pokkah boeng disease.

As a vital cash crop and bioenergy feedstock, sugarcane plays a pivotal role in global agriculture and renewable energy systems. The emergence of pokkah boeng disease has become a critical threat to sugarcane productivity. Current diagnostic methods face challenges in field-applicable early detection due to time-consuming procedures and insufficient sensitivity. This study pioneers a "Lab-on-Cloth" electrochemical biosensor that synergizes DNA nanorobotics with 2D graphyne for ultra-precise detecting of pathogen. The biosensor integrates three synergistic innovation mechanisms: a spatially confined DNA Walker system enabling programmable strand displacement cascades upon target recognition, sulfur-doped graphyne (S-GDY) nanoarrays providing enhanced electron transfer efficiency and catalytic current density, and a dual-signal readout strategy for self-verifying detection accuracy. The biosensor fabrication involves in fixing of AuNPs/S-GDY heterostructures on flexible carbon cloth, creating a hierarchical 3D conductive network. Upon pathogen DNA binding, the DNA Walker initiates dual strand displacement amplification cycles, generating distinct current responses through potential-resolved signal decoupling. This dual-signal readout achieves an ultra-low limit of detection (16.6 aM, S/N = 3) with a dynamic range spanning six orders of magnitude (0.1 fM-10 nM), outperforming conventional qPCR in field tests. This spatial DNA nanorobotics-graphyne synergy establishes a new paradigm for plant disease monitoring, providing real-time phyto-diagnostic capabilities. The technology's cost-effectiveness and operational simplicity position it as a transformative tool for precision agriculture and sustainable bioenergy production.