Duplex EIS Sensor for Salmonella Typhi and Aflatoxin B1 Detection in Soil Runoff

Area of Science:

• Environmental Science
• Food Safety
• Analytical Chemistry

Background:

• Contamination monitoring in agricultural soil and food is crucial for public health.
• Traditional lab methods are slow, costly, and not suitable for field use.
• Need for rapid, on-site detection of pathogens and toxins.

Purpose of the Study:

• Develop a portable sensing platform for simultaneous detection of Salmonella Typhimurium (S. Typhi) and Aflatoxin B1.
• Enable rapid, label-free, and selective detection in soil run-off samples.
• Validate the sensor's performance for real-time environmental and food safety surveillance.

Main Methods:

• Utilized a non-faradaic electrochemical impedance-based sensing platform.
• Employed ZnO-coated electrodes functionalized for antibody immobilization.
• Integrated a handheld potentiostat for impedance measurements and machine learning for classification.

Main Results:

• Achieved detection limits of 1 CFU/mL for S. Typhi and 0.001 ng/mL for Aflatoxin B1.
• Demonstrated high correlation (R² > 0.95) with benchtop results.
• Showcased high precision (recovery > 80%, CV < 15%) and reliable classification (ROC-AUC > 0.8).

Conclusions:

• The developed duplex sensing platform provides a robust and user-friendly solution for simultaneous detection.
• It offers a viable alternative to traditional methods for on-site screening.
• Enhances capabilities for real-time environmental and food safety monitoring.