Laser-modulated MnBi₂Te₄ terahertz biosensor for high-sensitivity marine bacterial detection.

Area of Science:

• Materials Science
• Biophysics
• Environmental Science

Background:

• Accurate identification of marine bacteria is crucial for ecosystem health and contamination control.
• Existing methods for bacterial detection can be time-consuming or require labeling.

Purpose of the Study:

• To develop a label-free terahertz (THz) biosensor for prompt and precise marine bacteria identification.
• To leverage magneto-topological MnBi2Te4 thin films and their unique quantum anomalous Hall effect for enhanced detection.

Main Methods:

• Utilized magneto-topological MnBi2Te4 thin films with surface engineering and laser modulation.
• Employed terahertz (THz) spectroscopy for label-free detection of bacteria and specific proteins.
• Validated sensor performance in natural seawater samples across various latitudes.

Main Results:

• Achieved a detection limit of 9.4 CFU/mL for Ruegeria pomeroyi DSS-3.
• Identified distinct THz absorption signatures for bacterial proteins sulfide-quinone oxidoreductase (SQR) and flavocytochrome c subunit B (FccB).
• Demonstrated minimal environmental interference (<1%) in natural seawater, confirming sensor robustness.

Conclusions:

• Pioneering integration of topological materials with THz photonics for marine biomonitoring.
• The developed biosensor offers a biocompatible, non-destructive, and cost-effective platform for real-time detection.
• This technology enhances capabilities for assessing marine ecosystem health and managing microbial contamination.