Laser-modulated MnBi2Te4 terahertz biosensor for high-sensitivity marine bacterial detection
摘要
The prompt and precise identification of marine bacteria is essential for assessing ecosystem health and mitigating microbial contamination in aquatic environments. In this study, we introduce a terahertz (THz) biosensor that utilizes magneto-topological MnBi2Te4 thin films, capitalizing on their quantum anomalous Hall effect and surface-dominated optoelectronic characteristics for label-free bacterial detection. Through the application of surface engineering and laser modulation techniques, the sensor achieves a detection limit of 9.4 CFU/mL for Ruegeria pomeroyi DSS-3, exhibiting adjustable THz photoresponses under ambient conditions. Notably, distinct THz absorption signatures were identified for the bacterial proteins sulfide-quinone oxidoreductase (SQR) and flavocytochrome c subunit B (FccB), with responsivity values ranging from 0.018 to 0.042 A/W at 0.1 THz. Field validation conducted in natural seawater across various latitudes (20–38°N) demonstrated minimal environmental interference (< 1%), indicating the sensor's robustness in complex marine matrices. This research represents a pioneering effort in the integration of topological materials with THz photonics, providing a biocompatible, non-destructive, and cost-effective platform for real-time biomonitoring in marine environments.
Graphical Abstract