A target-triggering strategy for self-powered biosensor based on chemical nanogenerator

The self-powered sensing platform uses redox reactions to convert chemical nanogenerators into electrical energy, powering the system for target detection. In this work, a multi-dimensional hollow C@SnO₂ nanocomposite is designed as the electrode substrate and combined with the catalytic hairpin assembly (CHA) amplification strategy. This platform enables highly sensitive detection of the breast cancer marker miRNA-145. C@SnO₂ provides a large specific surface area and excellent electron transport properties, offering abundant enzyme active sites and improving electron transport efficiency. In the presence of miRNA-145, the CHA reaction cycle is triggered, anchoring CHA products to the electrode surface. These signal molecules then participate in the electrochemical reaction, amplifying the signal. Under optimized conditions, the platform demonstrates a linear response range from 1 fM to 10 nM, with a detection limit as low as 0.78 fM. The self-powered sensor enabling sensitive detection of miRNA-145 at low concentrations which is crucial for the early diagnosis of breast cancer. Additionally, this work integrates the self-powered sensing platform with commercial chips, ensuring stable performance and minimal signal fluctuations during long-term continuous monitoring, enabling portable and real-time target monitoring. This design expands the application range of self-powered biosensors and offers new approaches for field detection of other targets.