Ultrasensitive detection of Vibrio cholerae O1 using microcantilever-based biosensor with dynamic force microscopy

Area of Science:

• Biosensing
• Nanotechnology
• Microbiology

Background:

• Cholera, caused by Vibrio cholerae O1, remains a significant public health concern.
• Accurate and rapid detection of V. cholerae O1 is crucial for food safety and public health surveillance.
• Existing detection methods often require pre-enrichment steps, increasing detection time.

Purpose of the Study:

• To develop and demonstrate a novel cantilever-based biosensor for the sensitive detection of Vibrio cholerae O1.
• To evaluate the performance of the biosensor in terms of detection limit and sensitivity.
• To confirm the specific binding of V. cholerae O1 to the sensor surface.

Main Methods:

• Utilized dynamic force microscopy with an atomic force microscope (AFM) to measure resonance frequency shifts.
• Immobilized monoclonal antibodies (anti-V. cholerae O1) onto gold-coated AFM microcantilevers using self-assembled monolayers.
• Tested the sensor with V. cholerae O1 concentrations ranging from 1x10^3 to 1x10^7 CFU/ml.
• Confirmed antigen-antibody binding using scanning electron microscopy (SEM).

Main Results:

• Achieved a detection limit of approximately 1x10^3 CFU/ml for V. cholerae O1.
• Demonstrated a mass sensitivity of ~146.5 pg/Hz, significantly higher than other reported techniques.
• The sensor enabled detection without the need for pre-enrichment steps, offering a significant advantage.
• SEM confirmed the specific binding of V. cholerae O1 to the antibody-functionalized microcantilever.

Conclusions:

• The developed microcantilever-based biosensor offers a promising platform for high-sensitivity, uncomplicated, and rapid detection of Vibrio cholerae O1.
• This technology has the potential for real-time monitoring of V. cholerae O1 in food products.
• The sensor's performance suggests its utility in food safety applications and public health diagnostics.