A flexible self-supported electrochemical sensor Co-NC/PS@CC for real-time detection of cell-released H₂O₂

Hydrogen peroxide (H₂O₂) is an important reactive oxygen species (ROS) molecule involved in cell metabolism regulation, transcriptional regulation, and cytoskeleton remodeling. Real-time monitoring of H₂O₂ levels in live cells is of great significance for disease prevention and diagnosis.

We utilized carbon cloth (CC) as the substrate material and employed a single-atom catalysis strategy to prepare a flexible self-supported sensing platform for the real-time detection of H₂O₂ secreted by live cells. By adjusting the coordination structure of single-atom sites through P and S doping, a cobalt single-atom nanoenzyme Co-NC/PS with excellent peroxidase-like activity was obtained. Furthermore, we explored the enzyme kinetics and possible catalytic mechanism of Co-NC/PS. Due to the excellent flexibility, high conductivity, strong adsorption performance of carbon cloth, and the introduction of non-metallic atom-doped active sites, the developed Co-NC/PS@CC exhibited ideal sensing performance. Experimental results showed that the linear response range for H₂O₂ was 1-17328 μM, with a detection limit (LOD) of 0.1687 μM. Additionally, the sensor demonstrated good reproducibility, repeatability, anti-interference, and stability.

The Co-NC/PS@CC prepared in this study has been successfully applied for detecting H₂O₂ secreted by MCF-7 live cells, expanding the application of single-atom nanoenzymes in live cell biosensing, with significant implications for health monitoring and clinical diagnostics.